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STUDIES  IN  ELECTRO-PHYSIOLOGY 


STUDIES 

IN 

ELECTRO-PHYSIOLOGY 

(^Animal  and  Vegetable) 

By 

ARTHUR    E.    BAINES 

CONSULTING   ELECTRICIAN 
Author  of  "  Electro- Pathology  and  Therapeutics,"  etc. 


WHH      THIRir-ONE      ORIGINAL     DRAWINGS 

IN  COLOUR,  ILLUSTRATING  THE  ELECTRICAL 

STRUCTURE    OF    FRUITS    AND     VEGETABLES 

By 

GLADrS     T.    BAINES 

And    numer  ous    other    Illu  s  tr  ations 


NEW  YORK 
E.  P.  BUTTON  AND  CO. 

LONDON  :  GEORGE  ROUTLEDGE  &  SONS,  LTD. 
1918 


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PRINTED  IN  GBEAT  BBITAIN  BY  THE  ANCHOR  PBESS  LTD     TDPIBEE  ESSEX. 


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THIS    WORK    IS    DEDICATED 
TO 

THE   MEDICAL   PROFESSION 

IN    THE    HOPE 

THAT    IT    MAY    INTEREST    AND    INSTRUCT,    AND 

PAVE    THE    WAY 

TO 

FRESH    CLINICAL    ADVANCE 

.      ALONG 

THE    LINES    HEREIN 

SUGGESTED 


PREFACE 

I  HAVE  been  encouraged  by  several  medical  friends,  and 
particularly  by  my  fellow  students,  Drs.  White  Robertson 
and  E.  W.  Martin,  to  make  an  excursion  into  the  realm  of 
Electro-physiology  ;  a  subject  which  I  had  previously  been 
reluctant  to  take  up  in  the  declining  years  of  my  life  owincy 
to  the  controversy  which  any  new  view  of  the  operating 
forces  of  the  body  would  be  sure  to  provoke.  But  the 
matter  at  issue  is  too  important  for  personal  considerations 
to  outweigh  a  possible  advance  in  knowledge. 

For  more  than  half  a  century  theories  which  were 
without  any  real  scientific  basis  have  barred  the  way  to 
progress,  and  the  rebutting  evidence  hitherto  at  command 
was  in  itself  insufficient  to  compel  adequate  attention, 
although  it  was,  upon  careful  examination,  enough  to  refute 
the  theories  in  question. 

In  a  former  work*  of  an  unambitious  character  I 
considered  the  nature  and  distribution  of  nerve  force  from 
a  new  standpoint,  and  it  followed  that  if  I  had  discovered 
a  fundamental  principle  my  research  work  must  harmonise 
with  established  laws  and  enable  me,  in  accordance  with 
those  laws,  to  explain  not  only  the  nature  and  source  of 
the  force  but  to  show  how  by  its  means  the  various  func- 
tions of  the  body  were  called  into  operation. 

The  two  theories  of  the  nature  of  the  nerve  impulse, 
the  physiological  and  the  physical,  are,  in  the  present  state 
of  our  acquaintance  with  the  subject,  equally  unsatisfac- 
tory, but  it  has  always  been  clear  to  my  mind  that  upon 
investigation  the  body  structure  should  make  it  manifest 
whether  it  was  primarily  designed  for  electrical  or  chemical 
functions ;  or  rather,  whether  it  was  evident  from  its 
*  Electro-Pathology  and  Therapeutics. 
vii 


viii  PREFACE 

structure  that  electrical  action  was  precedent  to  chemical 
change.  If  not,  if,  on  the  contrars^,  the  body  consisted  of 
a  congeries  of  chemical  laboratories,  with  only  an  oc- 
casional suggestion  of  an  electrical  circuit,  then  I  was 
self -deceived. 

To  this  day  we  electricians  do  not  know  if  in  a  galvanic 
cell  electrical  begets  chemical  action  or  vice  versa.  But  in 
the  form  and  appearance  of  a  galvanic  cell  there  is  nothing 
to  guide  us  to  definite  opinion,  much  less  to  afford  con- 
clusive proof.  What  is  electricity  ?  There  are  the  one- 
fluid  and  two-fluid  theories.  Dr.  Le  Bon  has  found  that 
the  particles  emitted  from  an  electrified  point  are  identical 
with  those  of  radimn  ;  carbon  when  suitably  treated  will 
give  off  a  form  of  energy  resembling  electricit}^  but  which 
can  be  shown  to  be  some  other  element — if  electricity  is  an 
element.  We  talk  glibly  of  ions  and  electrons — although 
we  know  very  little  about  them — and  are  constantly 
advancing  new  theories  as  if  they  wereiav>'S,  and  endeavom'- 
ing,  and  failing,  to  make  results  agree  with  them.  There 
is  only  one  law,  and  upon  that  law  all  creation  is  founded  ; 
one  law  for  the  living  and  a  modification  of  it  for  the  dead. 
There  are,  of  course,  differences  of  structure  and  jDcrfection 
of  structure,  but  the  same  law,  as  I  hope  to  show  in  these 
pages,  governs  without  exception  everything  that  lives 
upon  this  earth,  animal  and  vegetable  alike. 

A.   E.   BAINES. 

London.  1918. 


TABLE  OF  CONTENTS 

Page 

PRF.FAP.E     ....  -  -  -      VII 


ERRATA 

Page  34  ;  line  5.    For  "  Separates  it  "  reaA  "  Separates  the 
foliage." 

Page  57  ;    line  1.    Fm  "  2,000  "  and  "  40  "  rend  "  200  " 
and  "  400." 

Page  95  ;  line  2.     For  "  15  and  5  "  read  "  5  and  15." 
Page  98  ;   line  5.     For  "  points  are  "  read  "  points  is." 

Page  119  ;  fig.  31.  For  "  controsphere  "  read  "  centro- 
sphere." 

Page  143  ;  line  29.  For  "  Gynostemium  "  read  "  Gymnos- 
tenuum." 

Page  169  ;   line  20.     Fm  "  SO4  "  read  "  SOg." 
Page  172.     Inverted  commas  should  commence   on   line 
30,  after  "  subject." 

Page  173  ;  line  20.  For  "  to  the  lower  thigh-bone  "  read 
"  to  the  leg  bone."  Line  28  :  For  "  upper  and  lower  thigh- 
bones "  read  "  upper  and  lower  bones." 


REVIEW  OF  ELECTRO-PHYSIOLOGICAL  RESEARCH  49 

CAUSES  WHICH  HAVE  CONTRIBUTED  TO  ERROR  54 

THE  NATURE  OF  THE  NERVE  IMPULSE     -                  -  73 

INDUCTIVE    CAPACITY   -                   -                  -                 -  91 

CELL    REPRODUCTION     -                   -                 -                 .  103 

ix 


viii  PREFACE 

structure  that  electrical  action  was  precedent  to  chemical 
change.  If  not,  if,  on  the  contrary,  the  body  consisted  of 
a  congeries  of  chemical  laboratories,  with  only  an  oc- 
casional suggestion  of  an  electrical  circuit,  then  I  was 
self -deceived. 

To  this  day  we  electricians  do  not  know  if  in  a  galvanic 
cell  electrical  begets  chemical  action  or  vice  versa.     But  in 
th^  fni-m  and  a.nnearance  of  a  ffalvanic  cell  there  is  nothing 
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TABLE  OF  CONTENTS 

Page 

PREFACE vii 

INTRODUCTION         -         -  -  -  -   xxv 


PART   I 

ELECTRICAL    STRUCTURE    AND    FUNCTION 
IN   PLANT   LIFE: 

^                GENERAL                -                  -                  -                  -                  -  3 

DO  VEGETABLES  AND  FRUITS  POSSESS  CAPACITY  ?  17 

SOME    SEEDS    IN   THEIR   ELECTRICAL   ASPECT       -  22 

THE  ELECTRODES  AND  ELECTROLYSIS     -                  -  35 

PRIMARY    OR   SECONDARY    CELLS  ?            -                  -  36 

WATER  IN  ITS   RELATION   TO   PLANT  LIFE              -  38 

THE      EFFECT      OF      ELECTRICAL      STIMULATION 

UPON    GROWTH  -  -  -  -         39 

THE    EMPLOYMENT    OF    ELECTRICITY    IN    AGRI- 
CULTURE -  -  -  -  -         42 

NOTE  FOR  GUIDANCE  IN  TESTING  -  -         44 

PART  II 
STUDIES   IN   ELECTRO-PHYSIOLOGY: 

REVIEW  OF  ELECTRO-PHYSIOLOGICAL  RESEARCH  49 

CAUSES  WHICH  HAVE   CONTRIBUTED  TO  ERROR  54 

THE  NATURE  OF  THE  NERVE  IMPULSE     -                  -  73 

INDUCTIVE    CAPACITY   -                    -                  -                  -  91 

CELL    REPRODUCTION     -                   -                 -                 -  IQS 

ix 


X  TABLE   OF  CONTENTS 

Part  II.    Continued. 

Faob 

SEGMENTATION   OF   THE    OVUM                   -                 -  110 

ANIMAL   MAGNETISM        -                  -                 -                 -  116 

SOME   EVIDENCES    OF   THE   LAW                 -                 -  118 

AMOEBOID   MOVEMENT    -                 -                 -                 -  138 

STRIATED   MUSCULAR   TISSUE     -                 -                 -  144 
SARCOLEMMA   AND    NEURILEMMA               -                 ^161 

OTHER   INSULATING    PROCESSES                  -                 -  161 

TERMINATION  OF  NERVES  IN  MUSCLE     -                 -  165 

DENDRONS    AND    SYNAPSES          -                 -                 -  168 

CONNECTION   OF   MUSCLES   AND   BONES                    -  172 

RESPONSE   OF   MUSCLES  AND   NERVES   TO  ELEC- 
TRICAL   STIMULATION                  -                 -                 -  178 

CARDIAC   MUSCLE              -                 -                 -                -  182 

PLAIN   MUSCLE                    -                 -                 -                 -  184 

NISSL's    GRANULES           -                 -                 -                 -  189 

THE   NODES    OF   RANVIER              -                 -                 -  192 

GANGLION   CELLS               .                 -                 -                 -  196 

UNIPOLAR  AND   BIPOLAR   CELLS                -                 -  203 

MULTIPOLAR   CELLS         -                -                -                 -  205 

THE   EYE               -----  217 

THE   EAR               -                 -                 .                 -                 -  228 

electro-diagnosis      -            -            -            -  234 

ohm's  law       -----  245 

the  interpretation  of  certain   electro- 
physiological phenomena             -            -  251 

APPENDIX  : 

ELECTRICAL   CONDITIONS   OF  THE   EARTH             -  267 

ELECTRICITY  IN  RELATION  TO  SOME  VEGETABLE 

POISONS             -----  277 


LIST    OF    ILLUSTRATIONS 


PART    I— /n  Colour 

ELECTRICAL  STRUCTURE    AND    FUNCTION    IN    PLANT    LIFE 

Plate  I-II.  Apple            .....  fa£e  p.  10 

Plate  III-IV.  Banana         .....  face  p.  11 

Plate  V.  Tomato         .....  face  p.  10 

Plate  VI.  Orange          .....  face  p.  10 

Plate  VII-VIII.  Lemon           .....  face  p.  11 

Plate  IX-XI.  Turnip           .....  face  p.  12 

Plate  XII.  Carrot           .....  face  p.  13 

Plate  XIII.  Onion            .....  face  p.  IS 

Plate  XIV-XV.  Potato           .....  face  p.  14 

Plate  XVI-XVII.    Artichoke  ....  face  p.  15 

Plate  XVIII.  Horse-Chestnut  Leaf            .             .             .  face  p.  16 

Plate  XIX.  Ivy  Leaf       .....  face  p.  16 

Plate  XX.  Onion            .....  face  p.  17 

Plate  XXI.  Onion           '.....  face  p.  17 

Fig.  21a.  Diagram  of  Connections  {not  Coloured)        .  p.  18 


PART  I— Black  and  White 

Fig. 

22.  Section  of  Horse-Chestnut 

23.  Section  of  Horse-Chestnut 

24.  Showing  how  Induction  takes  place 

25.  Section  of  Horse-Chestnut  Seed 

26.  Horse-Chestnut  Seed 

27.  Sections  of  Horee- Chestnut  Seed 

28.  Section  of  Edible  Chestnut 

29.  Section  of  Edible  Chestnut 
80.  Acorns 

31.  Double  Acorn  in  Section 

32.  Cluster  of  Cob-Nuts 
88.    Foliage  and  Cup  of  Cob-Nut  opened  out 

xi 


Page 
23 

24 
25 
26 
26 
27 
30 
30 
32 
33 
34 
34 


XII 


LIST   OF  ILLUSTRATIONS 


PART^  11— Black  and  White 


FiGv, 
1. 


Thumb^pressure  upon  Electrodes 

2.  Condenser 

3.  Conventional  Drawings  of  Condenser 

4.  Conventional  Drawings  of  Condenser 

5.  Condenser  joined  up  with  Battery 

6.  Condensers  in  Parallel 

7.  Condensers  in  Series 

8.  Condensers  in  Series 

9.  Condensers  in  Series 

10.  Condensers  in  Series 

11.  Suggested  Connection  of  Endplates  with  Muscle 

12.  Diagram  of  Connections  for  Capacity  Test 
13-20.     Illustrating  Mitotic  Division 
21-22.     Illustrating  Segmentation  of  the  Ovum 

23.  Illustrating  Cell  Division 

24.  Lines  of  Force  of  Bar  Magnet 

25.  Lines  of  Force  of  Two  Bar  Magnets 
26-33.     Illustrating  Phases  in  Cell  Reproduction  in  Animal 

34.  Fertilisation  of  the  Ovum  of  a  Mammal 

35.  Oosphere  -with  Spermatozoids 

36.  Ganglion  Cell  (Human) 

37.  Spore  of  Vaucheria  Sessilis 
88.  Section  of  Spinal  Cord  (Human) 

39.  Transverse  Section  through  a  Root 

40.  Unipolar  Cell  of  Rabbit 

41.  Section  of  a  Branch  of  Usnea  Barbata 

42.  Fibrils  in  the  Sheath  of  a  Nerve-Fibre 

43.  Cells  from  a  Leaf  of  Hoya  Carnosa 

44.  Formation  of  Blastoderm  in  Rabbit 

45.  Division  of  Pollen  Mother  Cells  of  Plant 

46.  Group  of  Cartilage  Cells 

47.  Division  of  Pollen  Mother  Cells  of  Plant 

48.  Transverse  Section  of  Sciatic  Nerve  of  Cat 

49.  Parenchyma  Cell  from  Cotyledon  of  Plant 

50.  Fibro-Cartilage  Cells 

51.  Cells  from  Cortical  Tissue  of  the  Stem  of  a  Plant 

52.  Section  of  SaUvary  Gland  (Human) 

53.  Glandular  Colleter  of  Plant 

54.  Muscular  Fibre-Cell  (Human)     . 

55.  A  Vegetable  Fibre 


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104-108 

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118-119 

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LIST   OF  ILLUSTRATIONS 


Xlll 


Part  II — -Black   and  White.     Continued. 

Fig. 

56.  Diagram  of  Pregnant  Human  Womb 

57.  Ovule  of  a  Gymnosperm  .... 

58.  Epithelium  Cells  (Human) 

59.  Peripheral  Protoplasm  of  the  Embryo  Sac  of  Plant 

60.  Endothelium  of  a  Serous  Membrane  (Human)     . 

61.  Cells  from  a  Tendril  of  a  Plant    . 

62.  Section  across  a  Nerve  Bundle  (Dog) 

63.  Section  through  a  Young  Internode  of  Plant 

64.  Capillary  Vessels  of  the  Air  Cells  of  Lung  (Horse) 

65.  Laticiferous  Vessels  from  Root  of  a  Plant 

66.  Injected  Blood-Vessels  of  Muscle  (Human) 

67.  United  Latex  Vessels  of  Plant 

68.  Stomata  in  Different  Stages  of  Opening  and  Closing 

69.  Cells  from  the  Leaf  of  a  Plant     . 

70.  Cells  from  a  Staminal  Hair  of  a  Plant     . 

71 .  Electrical  Diagram  of  Voluntary  Muscular  Fibre 

72.  Physiological  Diagram  of  Voluntary  Muscular  Fibre 

73.  Electrical  Diagram  of  Voluntary  Muscular  Fibre 
74-76.     Illustrating  Expansion  and  Contraction  of  Muscle 

77.  Diagrammatic 

78.  Connection  of  Nerve  with  Muscle 

79.  Connection  of  Nerve  with  Muscle 

80.  Connection  of  Nerve  with  Muscle 

81.  Sarcomere  in  Moderate  Extension 

82.  Sarcomere  in  Contracted  Condition 

83.  Portion  of  Leg  Muscle  of  Insect 

84.  Muscle  Curve 

85.  Section  of  Sciatic  Nerve  of  Cat 

86.  Section  of  Screened  Cable 

87.  Termination  of  Nerve-Fibre  in  Tendon 

88.  Plexus  of  Auerbach 

89.  Illustrating  Molecular  Theory  of  Electricity 

90.  Synaptic  Connections  of  a  Sympathetic  Cell 
91-91A.     A  Synapse  (Diagrammatic)  . 
92.  A  Synapse  (Diagrammatic) 
93-94.     Illustrating  the  Parallelogram  of  Forces 
95.  Muscular  Fibre  Cell  (Small  Intestine)     - 
96-99.     Illustrating  Contraction  of  Same  (Diagrammatic) 

100.  Muscle  Cells  of  Intestine 

101.  Anterior  Horn  Cell  with  Processes 


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134 
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147 
148 
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152 
153 
160 
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163 
165 
167 
169 
170 
170-171 
171 
176 
184 
186 
187 
190 


XIV 


LIST   OF  ILLUSTRATIONS 


Part  II — Black  and  White.     Continued. 

Fig. 

102.  Showing  a  Node  of  Ranvier      . 

103.  Showing  a  Node  of  Bamboo 

104.  Degeneration  of  Nerve  to  Node  of  Ranvier 

105.  Diagram  of  Chain  of  the  Sympathetic 

106.  Neurons  of  the  Motor  Path  (Physiological) 

107.  The  same  reproduced  artificially 

108.  Forms  of  Spinal  Ganglion-Cells 

109.  A  Unipolar  Cell  (Rabbit) 

110.  A  Bipolar  Cell  (Fish) 

111.  Sketch  of  Metallic  Ball  for  Electrification 

112.  A  Multipolar  Cell  (Physiological) 

113.  A  Multipolar  Cell  (Electrical) 

114.  A  Multipolar  Cell  (Electrical) 

115.  A  Multipolar  Cell  (Fish) 

116.  Reflex  Action 
117.'  Root  Fibres  of  the  Cranial  Nerves 

118.  Plan  of  the  Origin  of  the  Fifth  Nerve    . 

119.  Pigmented  Cells  of  the  Retina 

120.  Section  through  the  Human  Eye 

121.  Section  through  the  Macula  Lutea  and  Fovea 

122.  Diagrammatic  Section  of  the  Human  Retina 

123.  Scheme  of  the  Organ  of  Hearing 

124.  Square  Case  Kelvin  Reflecting  Astatic  Galvanometer 

125.  Milled  Torsion  Head     . 

126.  A  d' Arson val  Galvanometer     . 

127.  Galvanometer  Scale  and  Lamp 

128.  Transparent  Galvanometer  Scale  and  Stand 

129.  Paraffin  Lamp  for  use  with  Galvanometer 
130-131.     Diaphragms 
182-133.     Short-Circuit  Keys 

134.  Electrode 

135.  Thumb-Piece 

136.  Method  of  Connecting 
137-138.     Electrodes 

139-140.     Diagrams  illustrating  Ohm's  Law 
141-142.    Diagrams  of  Fall  of  Potential 
143.     Illustrating  Deflection  in  Lobar  Pneumonia 
143A-143C.    Differences  of  Level  and  Potential 
144-146.     Illustrating  Earth  and  Cloud 


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256-7 
. 266-9 


SYNOPSIS   OF    PART   I 

ELECTRICAL    STRUCTURE    AND    FUNCTION    IN 
PLANT  LIFE 

CHAPTER    I 

GENERAL 

Pagr 
Application  of  electricity  to  the  soil — No  attempt  to  ascertain 
Nature's  methods — Experiments  not  conclusive — The  views 
of  Thome  and  Sachs — Analogies  in  animal  and  vegetable 
physiology — Electricity  plays  a  part  in  the  vegetable  as  well  as 
in  the  animal  worid — Everj'thing  living  has  a  well-defined 
electrical  system — The  edible  part  of  a  fruit  or  vegetable  is  the 
positive  element — ^Dry  earth  is  a  non-conductor  of  electricity 
— Water  required  as  an  electrolj'te — Conservation  of  energy  of 
vegetable  cells — Electromotive  force  of  vegetables,  plants  and 
fruits — Plants  grown  in  pots — Electrical  stimulation  of  growth 
— The  recording  instrument  and  electrodes — Sign  of  the  earth 
and  the  air — How  earth-grown  plants,  etc.,  are  charged — 
Method  of  testing  described — Theories  examined  and  disputed — 
Effect  of  diffusion  or  decay — The  apple  described  and  illustrated — 
How  a  cut  apple  endeavours  to  protect  itself  against  decay — 
The  banana  illustrated,  its  -positive  and  negative  systems — ^The 
tomato  illustrated — Difference  between  one  grown  in  the  open 
and  one  from  the  greenhouse — Effect  of  connecting  pot  with  the 
earth — The  orange  and  lemon,  illustrated  and  described — 
Peculiarity  of  absolute  insulation — ^The  turnip  illustrated — 
Defective  absolute  insulation  and  consequent  short  life  after 
removal  from  the  soil — No  adequate  means  of  protection — 
Effect  of  keeping  in  a  moist  condition  (illustrated) — The  carrot, 
illustrated  and  described — The  onion  (illustrated),  a  compound 
cell — Difficult  to  examine  galvanometrically — Perfect  absolute 
insulation — Its  electromotive  force  and  current — Invaluable  as 
a  standard  cell  ..--..-3 
Tubers  :  The  potato,  illustrated  and  described — ^Takes  its  current 
from  the  mother  plant — Prolific  and  unprohfic  eyes — How  it  is 
enabled  to  repair  injury — How  it  grows  (illustrated) — The 
Jerusalem  artichoke  (illustrated) — Takes  its  electrical  supply 
directly  from  the  earth  and  differs  in  other  respects  from  the 
potato — ^Leaves — Deciduous  and  evergreen — Differences  of  in- 
sulation and  life — The  horse-chestnut  and  ivy  (illustrated)       -       14 

XV 


xvi  SYNOPSIS 


Page 


Do  Vegetables  and  Fruits  possess  Capacity  ?  Answer  in  the  affirma- 
tive— ^Experiment  with  a  quince — How  the  tests  were  taken — 
Experiments  with  onion,  rhubarb,  apple,  banana,  turnip  and 
orange  described  -  -  -  -  -  -  -       17 


chapter  ii 
sojme  seeds  in  their  electrical  aspect 

Examination  of  seeds,  in  their  various  stages  of  development,  of 
great  interest — Some  analogy  between  some  immature  seeds 
and  the  human  foetus — Some  law  seems  to  govern  both  and  also 
cell-reproduction — The  Horse- Chestnut  seed  illustrated — 
Method  of  preparation  and  testing — Its  construction,  electrically 
considered — The  insulating  membranes  and  conducting  layer — 
How  the  seed-pod  is  charged  by  the  earth  and  the  air — Its 
influence  upon  the  seed  substance — Independent  existence  of 
the  seed  only  begun  when  it  falls  from  the  pod — Changes  which 
then  take  place  and  how  the  seed-substance  receives  charge 
(illustrated) — The  final  appearance  of  the  insulating  membranes 
(illustrated) — The  secretion  of  the  pod  and  seed-substance — 
Chemical  composition  of  the  membranes — A  contrast — The 
Edible  Chestntjt  (illustrated)  examined  and  tested — How 
different  to  the  horse-chestnut — Weird  suggestion  of  foetus  in 
womb — ^Higher  order  of  growth — Food  as  well  as  seed — How  it 
is  equipped  to  serve  as  both — Its  capacity  compared  with  that 
of  the  horse-chestnut — Hypothetical  explanation  of  the  purpose 
underlying  it — ^The  Acokn  (illustrated) — How  the  seeds  are 
joined  up  electrically — The  contacts  and  insulation — ^Twin 
seeds  and  how  they  are  given  protection — Cob-nuts  (illustrated) 
— ^How  joined  up  electrically  and  how  insulation  is  preserved,  etc.       22 

The  Electrodes  and  Electrolysis :     Experiments  to    determine  the 

effect  of  electrolysis  upon  the  deflections  observed        -  -       35 

Primary  or  Secondary  Cells  ?  Probably  neither — Cells  undergo  no 
disintegration  and  no  change — Cannot  be  polarised  or  discharged 
— ^Length  of  Ufe  in  direct  ratio  to  absolute  insulation — Effect  of 
short-circuiting — Plants  "  resting  "  in  late  autumn,  winter  and 
spring — Constancy  of  vegetable  cells — ^Theoretical  explanation 
of  their  long-sustained  electrical  activity  -  -  -       36 

Water  in  its  relation  to  Plant  Life  :  As  dry  earth  is  a  non-conductor 
of  electricity  water  is  also  required  as  an  electrolyte — Experi- 
ment with  mustard  and  cress,  ferro-sulphate  and  less  water — 
Some  suggestions  -  .....       38 


SYNOPSIS  xvii 

Pxas 

The  Effect  of  Electrical  Stimulation  upon  Groioth  :  Currents  artificially 
sent  through  a  root  said  to  retard  growth — Statement  not 
warranted  by  fact — Experiments  with  potatoes,  with  plants  in 
greenhouse,  and  with  onions — Question  of  polarity,  not 
electricity — Variously  stimulated  onions  illustrated       -  -       39 

CHAPTER   III 
THE  EMPLOYMENT   OF   ELECTRICITY   IN   AGRICULTURE 

Review  of  the  last  one  hundred  and  fifty  years — Results  considered — 
Chlorosis  in  plants — Iron  and  oxygen  in  plant  life — ^Periods  of 
drought — The  savoy  cabbage     -  -  -  -  -       42 

Note  for  Guidance  in  Testing  :   The  electrodes  and  how  to  connect 

them  (illustrated)  -  -  -  -  -  -       44 


SYNOPSIS   OF  PART   II 

STUDIES     IN     ELECTRO-PHYSIOLOGY :    ANIMAL 
AND   VEGETABLE 

CHAPTER   IV 
REVIEW  OF  ELECTRO-PHYSIOLOGICAL  RESEARCH 

Present  state  of  knowledge — Galvani,  Volta,  Humboldt,  Aldini, 
Nobili,  Matteucci,  Du  Bois-Reymond,  Radcliffe,  Trowbridge — 
Causes  of  confusion — Certain  factors  not  discovered      -  -       49 

Causes  which  have  Contributed  to  Error  :  Generation  and  dissipation 
of  nerve  force — Insulation  of  the  body — Air  and  earth — 
Individuals  differ  electrically — Conflicting  results  and  the 
reason  therefor — Personal  capacity — Capacity  of  liquids  and 
moist  substances — Non-polarisable  electrodes — Other  electrodes 
and  their  reliability — Dr.  Longridge's  experiments — Dr.  Martin's 
experiments — Other  tests  of  electrodes — Argument — "  Sugges- 
tion " — The  hand-to-hand  deflection  and  thumb-pressure — 
Structure  of  the  body  primarily  electrical         -  -  -       54 

CHAPTER  V 
THE  NATURE  OF  THE  NERVE  IMPULSE 

Rival  theories,  physiological  and  physical — Argument  that  impulse 
is  chemical  more  in  favour  of  it  being  electrical — Argument — 
Professor  Rosenthal  and  peripheric  nerves — Inhibition — Velocity 

b 


xviii  SYNOPSIS 


Page 


of  impulses  compared — Retardation — Resistance  of  copper 
•wire  compared  with  nerve — Normal  E.M.F.  and  current  of 
man — Effect  of  capacity — ^Hypothesis  of  Dr.  Martin — Natural 
dielectrics — Experiments  of  Dr.  Le  Bon  -  -  -       73 

CHAPTER   VI 

INDUCTIVE   CAPACITY 

The  effects  of  capacity — Apparent  velocity  of  current  diminished — 
Condenser  described — Connections  in  parallel  and  in  series — 
Joint  capacity  in  series — Current  and  resistance — ^Potential 
differences — Connection  in  series-parallel — Condensers  of  the 
human  body — Reflex  action — ^Rates  of  discharge — Condenser 
action  in  cardiac  muscle — Influence  of  capacity  upon  velocity  of 
the  nerve  impulse — Specific  inductive  capacity — ^Dimensions  of 
plain  and  voluntary  muscular  fibres — ^To  test  the  human  body 
for  capacity,  method  and  diagram         -  -  -  -       9i 

CHAPTER   VII 
CELL   REPRODUCTION 

Mitotic  division — The  centrosonxe  and  the  attraction  sphere — The 
centriole — ^Division  of  cell  preceded  by  division  of  the  attraction 
sphere — Changes  in  the  cell  during  the  process — ^Achromatic 
fibres  and  spindle — Chromatin — Chromosomes — Irritability  of 
protoplasm — Cleavage — Repulsion  as  well  as  attraction — 
Nucleus  and  nucleolus- — Division  briefly  described         -  -     103 

Segmentation  of  the  Ovum :  Hetero  and  homotypical  mitosis — 
Polar  bodies — ^Varying  number  of  chromosomes — Sperm  and 
germ  nuclei — Fertilisation — Ascaris  megalocephala — Difference 
from  ordinary  mitosis — Sexual  reproduction  in  plant  life — 
Mucor  and  spirogyra — Fucus — Asexual  reproduction — Fungi, 
diatomaceae  and  protozoa — Importance  of  nuclei — ^Network  in 
protoplasm — Enzyme  action — Vines'  description  of  Karyo- 
kinesis      -  -  --  -  -  -  -110 

CHAPTER  VIII 

ANIMAL    MAGNETISM 

Alleged  magnetic  influences  in  the  human  body — Not  warranted  by 
fact — ^Resemblance  of  certain  phenomena  to  magnetic  control 
superficial — Geddes  and  Thomson's  diagram  of  cell-division 
compared  with  lines  of  force  of  a  bar  magnet,  and  with  two  bar 
magnets  .......     hq 


SYNOPSIS  xix 

CHAPTER   IX 

SOME   EVIDENCES    OF   THE   LAW 

Page 
Phases  of  cell  reproduction,  animal  and  vegetable — Fertilisation  of 

the  ovum  and  oosphere — Ganglion  cell  and  spore — Spinal  cord 
and  root  of  Phaseolus  multiflortis — Unipolar  cell  and  section  of 
branch — Spinal  and  reticular  fibrils  (human)  and  cells  from  a 
leaf — Blastoderm  of  rabbit  and  pollen  mother  cells  of  plants — 
Cartilage  and  pollen  cells — Section  of  sciatic  nerve  and  cell  of 
plant — Fibro-cartilage  cells  and  thickened  cells  from  stem  of 
plant — Human  and  vegetable  glands — Cell  of  plain  muscular 
fibre  and  a  vegetable  fibre — Pregnant  human  womb  and  ovule 
of  a  gymnosperm — Epithelium  cells  (human)  and  peripheral 
protoplasm  of  embryo-sac  of  a  plant — Endothelium  of  a  serous 
membrane  (human)  and  cells  froni  a  tendril  of  a  plant — Section 
across  a  nerve  in  the  second  thoracic  anterior  root  of  a  dog  and 
section  through  internode  of  the  short  axis  of  a  plant — Capillary 
vessels  of  the  air-cells  of  horse's  lung  and  laticiferous  vessels  of  a 
plant — Sachs  and  others  upon  laticiferous  vessels  in  plants — 
Injected  blood-vessels  of  a  human  muscle  and  reticulately 
united  latex  vessels  of  a  plant — Irritability  of  vegetable  proto- 
plasm— Similarity  of  senses — Motor  mechanism  of  plants — 
Stomata — Stimulation — Sense  organs  of  plants — Specific 
energies  of  the  sensory  nerves — Enzymes — Fats  in  plants — 
Wax  in  plants  and  fruits — Movement  or  circulation  of  proto- 
plasm in  plants — Cells  from  leaf  of  Elodea  and  hair  of  Trades- 
cantia — Rhythnuc  movement  in  plants — Paralysis  or  destruc- 
tion of  protoplasmic  movement — Rate  of  propagation  of 
stimuli  in  plants  ......     us 

CHAPTER   X 

AMOEBOID    MOVEMENT 

Movement  apparently  spontaneous — Nucleo-protein — All  breathing 
or  taking  in  oxygen — Nature  of  the  movement — Effect  of 
change  of  temperature,  chemical  stimuli,  electrical  stimuli,  etc. 
— Foregoing  paraphrased  and  explained — Live  and  dead 
amoeba — The  experiment  of  Ampere — Attraction  and  repulsion 
— Experiments  of  Davy,  Le  Bon  and  Arrhenius — Czapec  on 
salt  solutions — Inorganic  salts  in  the  blood  plasma — Rigor  or 
cessation  of  protoplasmic  movement  in  plants     -  -  -     138 

CHAPTER   XI 

ELECTRO-PHYSIOLOGY  OF  THE  MOTOR  APPARATUS 

Huecular  tissue — Striated  muscular  tissue — Anticipation  before 
studj— Sarcolemma  and  structure  of  the  sarcomeres — Krause's 
membranes  or  Dobie's  lines — Chemical  or  electrical  action  ? — 


XX  SYNOPSIS 


Fasb 


Certain  electrical  laws — ^Physiological  aud  electrical  diagrams — 
Artificial  muscular  fibre — ^Discharge  or  neutralisation  of  charge 
— Further  diagrams — ^How  the  nerve-fibres  connect  Avith  groups 
of  sarcomeres — Muscle  extended  and  contracted — The  plane  of 
Hensen — Condenser-action — The  "  Muscle  Telegraph  "  of  Du 
Bois-Reymond — Physiology  of  muscular  fibre  considered — 
Stimuli  not  various  forms  of  energy — Clear  spaces  may  be 
"  points  " — StimuU  not  discharging  forces — Effect  of  rise  or 
fall  of  temperature  upon  muscular  fibre — Excised  muscle — 
Difference  between  the  living  and  the  non-living — Comparison 
with  frog,  toad  and  tortoise — Excitability  of  muscle  when  nerve 
dead — Compared  with  apple — Independent  muscular  activity 
reviewed — Wrong  to  say  plants  have  no  nerves — ^Reasons 
therefor — Effect  of  poisons  upon  nerves  and  plants — Curara 
and  nux  vomica — Muscle-curve  due  to  single  induction  shock 
examined  --------     144 

Sarcolemma  and  Neurilemma  :   Both   elastic  and  both  dielectric  in 

character — Argument  -  -  -  -  -161 

Other  Insulating  Processes  :  Sciatic  nerve  of  cat — Endoneurium, 
perineurium  and  epineurium — The  electrical  function  of  lymph 
— Insulation  of  submarine  and  screened  land  cable — Inductive 
interference  -  -  -  -  -  -  -     161 

The  Termination  of  Nerves  in  Muscle  :  End -organs — Fibres  branch 
— MeduUated  nerve-fibres — Plexuses  of  involuntary  muscle — 
Each  nerve-fibre  separately  insulated — Plexus  of  Auerbach        -     166 

Dendrons  and  Synapses  :  Cells  of  Purkinje — ^Neuroglia  and  con- 
nective tissue — Dendrons,  axon  and  neuron — Cell  processes — 
Synaptic  junctions — Contiguous  but  not  continuous  structures — 
Propagation  of  electric  force  by  molecular  action — Sympathetic 
cell  :  arborisations — Physiological  path  of  chains  of  neurons 
uninterrupted — Synapse  compared  with  condenser — ^Necessity 
for  insulating  processes  in  the  body       -  -  -  -     168 

Connection  of  Muscles  and  Bones  :  Whole  action  of  muscle  the  sum 
of  the  separate  actions  of  all  the  fibres — Fan-shaped  muscles — 
Semi-pennate  muscles — Pennate  muscles — Parallelogram  of 
forces — Work  performed  by  muscles  conditioned  by  their 
attachment  to  the  bones — Sesamoid  bones        -  -  -     172 

Response  of  Muscles  and  Nerves  to  Electrical  Stimulation  :  Nutrition 
of  the  nerves — When  impaired — Nerve  degeneration  and  its 
effect  on  muscle — Changes  in  the  excitability  of  muscle — Con- 
tractions caused  by  constant  and  induced  currents — ^Degenera- 
tion of  motor  nerve — Response  of  muscle  to  constant  current — 
Afuscular  paralysis — Paralysis  due  to  disease     -  -  -     178 


SYNOPSIS  xxi 

CHAPTER    XII 

CARDIAC    MUSCLE 

Page 
Histological  diagrams  not  sufficiently  clear — Cardiac  muscle  inter- 
mediate— Each  segment  considered  as  a  sarcomere — Branch  or 
shunt  circuits — Regulation  exercised  by  the  cardiac  branches  of 
the  vagi — Day  and  night  intake  of  oxygen  in  relation  to  the 
hand-to-hand  galvanometric  deflection — Inhibition — Effect  of 
an  escape  of  nerve  energy,  and  of  certain  toxins  -  -     1 82 

Plain  Muscle  :  Very  little  information — Must  be  transversely  striated 
— Professor  Rosenthal's  views — Schafer — The  question  of  a 
sarcolenuna — Longitudinal  striation  would  only  cause  flattening 
— Explanatory  diagrams  and  speculative  explanation — How  the 
cells  are  probably  connected  up  ....     i84 

CHAPTER   XIII 

NISSL'S   GRANULES 

Cells  contain  organically  combined  iron,  but  not  in  masses  as  hitherto 
thought — Mott's  researches  viith  living  cells — Nissl's  granules 
the  result  of  coagulation  in  the  dead  cell — In  the  living  cell  they 
exist  in  the  form  of  fine  particles  -  -  -  -     189 

CHAPTER    XIV 

THE   NODES    OF   RANVIER 

Illustration  of  a  typical  node — How  the  nodes  occur — Compared  with 
bamboo  and  canes — Strasburger  on  the  nodes  of  bamboo — 
Degeneration  of  nerve  only  to  node — Uninterrupted  continuation 
of  axon  questioned — Constriction  and  increased  resistance 
suggested — Reasons    therefor      -  -  -  -  -     192 

CHAPTER   XV 

GANGLION   CELLS 

Some  said  to  be  condensers  and  some  storage  cells — Differentiation 
of  the  two — Efferent  and  afferent  impulses,  and  control  and 
regularity  of  supply — Diagram  of  motor  and  sensory  paths 
from  spinal  cord — The  functions  of  a  condenser  in  telegraphy — 
Diagram  of  unipolar  and  bipolar  cells — Maintenance  of  normal 
insulation  resistance — Physiological  and  electrical  diagrams  of 
motor  and  sensory  paths — Quantity  and  tension — The  views  of 
Dr.  Le  Bon — Confusion  of  terms — Electro-cardiograms  and 
ganglia — Thornton's  views — Autonomic  ganglia — Afferent  and 
efferent  fibres       -  -  -  -  -  -  -     196 


xxii  SYNOPSIS 

Page 
Unipolar  and  Bipolar  Cells  :  The  conducting  and  non-conducting 
cell-substances — Macallum  and  Turner — Forms  of  Leyden  jar 
and  condenser — ^Their  probable  connection — Cells  disposed  in 
aggregations  of  different  size — ^The  capsule  of  connective  tissue — 
Continuous  with  the  epineurium  and  perineurium — Branching 
of  the  axis-cylinder  process  at  node  of  Ranvier — ^Neuro-fibril 
network  within  cell  body — Every  cell  not  of  same  structure — 
Illustrations  from  Schafer  .....     203 

Multipolar  Cells  :  Cells  of  the  cerebral  cortex  and  spinal  cord — 
Construction  of  an  artificial  multipolar  cell  described — Surface 
area  and  tension — Physiological  and  electrical  diagrams — 
Dendrons  said  to  be  branch  circuits — How  to  take  off  efferent 
and  afferent  impulses  at  will — Arrangement  of  condensers  or 
bipolar  cells  described  and  illustrated — Multipolar  cell  made  up 
of  as  many  Leyden  jars  or  rings  as  there  are  dendrons  with 
separate  nerve-fibres  to  each — Illustration  from  Haeckel — 
Reflex  action  illustrated  and  discussed — Synaptic  junctions — 
Undifferentiated  interstitial  protoplasm — Storage  cells  in 
sensory  paths  illustrated — ^Not  found  in  motor  paths — Con- 
nection of  voluntary  motor  fibres  with  multipolar  nerve-cells  of 
the  anterior  cornu — Direct  motor  impulses  not  interrupted  in 
their  passage  through  the  brain  ....     205 

CHAPTER  XVI 

THE    EYE   AND  THE   EAR 

The  Eye  :  Strongly  suggestive  of  a  compoimd  selenium-cell  transmit- 
ting apparatus — The  effect  of  light  upon  selenium — Transmitting 
pictures  to  a  distance — The  telectroscope  described — Property 
of  selenium — Trans/nission  of  colour — Colour  in  relation  to 
white  light — The  lens  of  the  eye — The  iris  or  diaphragm — 
Pigment  cells  illustrated  and  described — ^The  rods  and  cones — 
Connections  at  the  fovea  and  elsewhere — ^The  macula  lutea — 
Visual  impulses  said  to  begin  in  the  rods  and  cones  on  the  outer 
side  of  the  retina — Latter  connected  functionally,  if  not  struc- 
turally, with  the  nerve  filaments  that  pass  to  the  optic  nerve — 
"  Visual  purple  " — Possible  function  of  the  epithelial  pigment 
cells  of  the  retina — Our  ignorance  of  how  undulations  of  light 
become  converted  into  nervous  impulses — Ordinary  light  and 
vibrations — The  eye  illustrated — Vertical  section  through  the 
macula  lutea — Diagrammatic  section  of  the  retina — Alleged 
vibrations  of  electrons  in  the  retina — Maxwell  and  the  speed  of 
electro-magnetic  waves — Duration  of  the  sensation  produced  by 
a  luminous  impression  on  the  retina — Optic  nerve  said  to  be  a 
closed  circuit — Movement  of  the  pigment  cells — Movement  of 
the  cones  and  possibly  of  the  rods  -  -  -  -     237 


SYNOPSIS  xxiii 

Page 
The  Ear  :   Physiological  description — Endolymph  and  perilymph — 

Passage    of    the    impulses — The    external    auditory    meatus — 

Malleus,  incus  and  stapes  illustrated  and  described — Mechanical 

impidse    questioned — Mechanism    of   hearing    far    from    being 

satisfactorily  settled — Neuro-electrical  theory  more  reasonable 

and  probable  than  chemical  or  mechanical — Proof  that  it  is  so — 

The    fenestra    ovalis — Basilar  membrane    and    membrane    of 

Reissner — Ear,  from  external  auditory  meatus  to  brain ,  said  to 

be    a    telephone    system — Auditory    nerves    closed    circuits — 

"  Faults  "  and  how  to  test  for  them       ....     228 

CHAPTER   XVII 

ELECTRO-DIAGNOSIS^THE    GALVANOMETER    AND 
ELECTRODES 

Chief  requirements  in  a  galvanometer — Its  required  sensibiHty  and 
period — Illustration  of  square  case  Kelvin — Its  adjustment — 
Its  advantages  and  drawbacks — Galvanometers  of  the  d'Arson- 
val  type  illustrated — Scales  illustrated — The  lamp  (illustrated) — 
Types  of  galvanometer  short-circuit  keys — Shunts — Connecting 
wires — Earth  connection— The  electrodes  illustrated  and  de- 
scribed— Sign  of  current  unimportant — All  deflections 
comparative  ---....     234 

CHAPTER   XVIII 

OHM'S   LAW 

In  its  application  to  the  human  body — Shortly  described — In  terms 
of  hydrostatics — Further  description — Resistance  of  metallic  and 
liquid  conductors — Fluctuation  of  human  E.M.F. — Influence  of 
capacity  of  condenser-ganglion  cells — Variation  of  potential — 
Temperature  and  moisture — Diagrams — Potential  differences  -  245 
The  Hmid-to-Hand  Deflection  :   Precautions  necessary  -  -     249 

Application  of  Ohm's  Law  to  Solutions  :  The  researches  of  Arrhenius  -     250 

CHAPTER   XIX 

INTERPRETATION   OF  CERTAIN  ELECTRO-PHYSIOLOGICAL 
PHENOMENA 

Dielectric  substances  and  structures  in  the  human  body — Effect  of 
heat  upon  all  known  dielectrics — Formula  for  calculating  the 
relative  resistance  of  gutta-percha — -Local  temperature  and 
local  pyrexia  and  the  effect  upon  local  insulation  resistance — 
Maxwell's  experiments — Heat  and  liquid  conductors — Effect  of 
heat  upon  the  dielectrics  of  the  body  as  compared  with  its  effect 


xxiv  SYNOPSIS 


Page 


upon  gutta-percha — Heat  and  protoplasm — Fault  in  a  sub- 
marine telegraph  cable  compared  mth  similar  fault  in  the  body 
— Path  of  least  resistance — Lobar  pneumonia — Exact  location 
of  fault — Double  pneumonia — Varying  conditions  of  contact 
and  moisture — Differences  of  potential  and  differences  of  level — 
Deflections  from  hot,  dry  skin — Nervous  weakness — Impaired 
conductivity  :  effect  of  certain  toxixis  upon  nerve  conductivity — 
Various  "  faults  " — Importance  of  the  galvanometer  in  obscure 
morbid  pathology — Efferent  and  afferent  branches  of  the  vagi    -     251 

Galvanometric  Tests  of  Other  Diseases  :  Disease  in  general — 
Neurasthenia  nervous  instability  as  well  as  nervous  weakness — 
Epilepsy,  its  distinguishing  features  and  symptoms — Suggested 
means  of  alleviation  by  shunting  the  nerve  current — ^Direct  - 
cause  of  fit — Cancer,  some  tests  of — Cancer  cells  non-conducting 
— Usefulness  of  galvanometer  in  defining  area  affected  -  -     260 


APPENDIX 

ELECTRICAL   CONDITIONS    OF   THE   EARTH 

The  influence  of  electrified  railways,  tubes  and  tram-lines — ^Earth 
conditions  during  thunderstorms — Earth  and  cloud  in  electrical 
relation — Lightning  and  its  path  through  the  atmosphere — 
How  the  body  may  be  influenced — The  earth  as  zero — The 
earth  electrically  "  patchy  " — The  Rio  Plata  and  mouths  of 
rivers — Earthquakes  and  thunderstorms  in  the  tropics — ^No 
definite  knowledge  of  the  causes  which  set  up  earth-currents — 
The  aurora  borealis — Atmospheric  electricity — Fulminic  matter 
— Thermal  origin  of  earth-currents  considered — The  distribution 
of  volcanoes— Uncertainty  as  to  their  condition — Earth-current 
in  the  far  North — Dry  or  dielectric  soils  and  their  possible  effect 
upon  the  atmosphere  and  health,  as  compared  with  conductive 
soils — The  torrid,  temperate,  and  frigid  zones — Atmosphere  as  a 
vitalising  agent  ......     267 

ELECTRICITY  IN  RELATION  TO  SOME  VEGETABLE  POISONS 

Rhubarb  and  other  leaves — Vegetable  poisons  and  dietary — ^The 
negative  parts  of  plants,  tobacco  and  tea-leaves — Suggested 
experiments  .......     277 


BIBLIOGRAPHY 280 


INTRODUCTORY 

Receiving  a  first  education  in  telegraphy  in  the  Post 
Office  under  my  uncle,  F.  E.  Baines,  C.B.,  First  Surveyor- 
General  of  Telegraphs,  and  Mr.  (afterwards  Sir)  Wni. 
Preece,  I  joined  the  service  of  the  Eastern  Telegraph 
Company  in  the  early  seventies,  and  as  the  story  of  how  I 
became  interested  in  electro-physiological  research  may 
not  be  without  interest,  some  personal  details  are  perhaps 
admissible. 

Much  about  the  time  of  which  I  am  writing  I  was  chief 
assistant  electrician — under  my  old  friend  Professor 
Andrew  Jamieson — of  the  cable-ship  The  John  Pender,  be- 
longing to  the  Eastern  Telegraph  Company  and  then 
engaged  in  repair  work  in  the  Red  Sea  and  Indian  Ocean. 

An  unfortunate  accident  to  my  chief  left  me  for  a  time 
in  charge,  and  I  had  as  one  of  my  juniors  for  a  brief  period 
A.  E.  Kennelly,  now  Professor  of  Electrical  Engineermg 
at  Harvard  University. 

Submarine  cables,  however,  are  not  always  breaking 
down,  and  during  an  idle  interval  in  the  year,  so  far  as  my 
recollection  serves  me,  1880,  my  employers  lent  me  to 
Mr.  Finlay,  of  the  Cape  Observatoiy,  to  assist  him  in 
correcting  longitudinal  data  by  means  of  time  signals 
transmitted  over  the  company's  cables  between  Aden  and 
Durban. 

It  was  necessary  to  receive  signals  upon  a  reflecting 

XXV 


xxvi  INTRODUCTORY 

mirror  instrument  while  listening  to  the  loud  ticking  of  the 
seconds  of  a  clock  specially  made  for  astronomical  work. 
The  signal  had  to  be  sent  from  one  end  and  recorded  at 
the  other  at  the  exact  tick,  and  Mr.  Finlay  showed  me  the 
importance  of  determining  my  personal  coefficient  of 
error  in  reading  in  order  that  allowance  might  be  m.ade 
for  it. 

Some  time  afterwards,  while  engaged  in  cable-testing 
at  Delagoa  Bay,  I  noticed  a  deflection  upon  the  scale  of 
the  Astatic  reflecting  galvanometer  for  which  I  could  not 
account,  and  upon  investigation  found  the  disturbing 
influence  to  proceed  from  my  own  body.  This  led  to  a 
series  of  experiments  which  convinced  me  that  a  force 
resembling  electricity,  if  not  identical  with  it,  was  con- 
stantly generated  in  the  bod}^  and  that  its  tension  was 
dependent  upon  the  state  of  health  of  the  subject. 

Some  few  years  later  I  was  invalided  home,  and  at  the 
instance  of  Sir  James  Anderson  and  Sir  John  Pender — to 
whom  the  journal  then  belonged — was  associated  in  the 
editorship  of  The  Electrician,  and  also  became  editor  of 
The  Electrical  Engineer.  In  the  latter  paper,  in  May, 
1885,  I  published  an  article  entitled  "  The  Human  Body 
as  a  Disturbing  Element  in  Electrical  Testing,"  from  which 
the  following  quotation  may  be  made  : — 

"  I  am  of  opinion  that  in  every  case  where  use  is  made 
of  an  unshunted  galvanometer  of  great  sensibility  the 
operator  should  be  careful  to  connect  himself  during  the 
test  with  an  earth  plate,  instead  of,  as  is  usual,  standing 
upon  some  insulating  substance.  This  conclusion  was 
forced  upon  me  years  ago.  I  was,  in  the  ordinary  course 
of  business,  comparing  a  10-microfaradcondenser  withoneof 
1-micro  capacity  by  Sir  William  Thomson's  "  (afterwards 


INTRODUCTORY  xxvii 

Lord  Kelvin)  "  method,  employing  a  very  sensitive  Astatic 
galvanometer  and  two  platinum-silver  resistances,  arranged 
so  that  a  difference  of  one  ohm  resistance  gave  me  a 
difference  of  0  001  microfarad  capacity.  The  insulation 
of  the  battery  and  other  apparatus  was  absolutely 
perfect ;  I  used  a  current  due  to  very  low  electro- 
motive force,  in  order  to  avoid  heating,  and  took  all  the 
precautions  which  are  laid  down  by  others  and  which  our 
own  experience  suggests.  The  10 -micro  condenser  varied 
in  the  most  inexplicable  manner  between  8-929  and  9  931 
micros.  In  all  there  might  have  been  a  hundred  readings 
taken,  each  time,  or  almost  each  time,  with  a  different 
result,  with  a  discrepancy  of  about  0001  micro,  and  it  was 
not  until  I  observed  a  slight  galvanometric  deflection  while 
the  battery  circuit  was  open  that  the  probable  cause 
suggested  itself  to  me.  During  the  course  of  some  experi- 
ments I  afterwards  made  under  different  conditions  to 
verify  the  idea  then  formed,  I  stood  as  closely  as  possible 
to  the  galvanometer  circuit,  and  upon  being  charged  with 
20  volts  produced  a  slight  inverse  deflection  upon  the 
galvanometer  ;  when  the  circuit  was  opened  a  slight  direct 
deflection  was  noticeable.  After  having  connected  myself 
with  an  earth  of  low  resistance  the  phenomenon  ceased  to 
manifest  itself  and  I  succeeded  in  getting  a  balance.  ' 

My  association  with  Mr.  Finlay,  short  as  it  was,  was 
fortunate.  Had  it  not  been  for  that  association  I  should, 
in  all  probability,  have  dismissed  the  vagaries  of  the 
galvanometer  as  being  due  to  leakage,  and,  so  far  as  I  am 
concerned,  the  axperiments  might  never  have  been  made. 

Hundreds  of  other  electricians  have  observed  the  same 
phenomena  during  the  last  thirty  or  more  years,  but  have 
not  bothered  themselves  to  do  more  than  attend  to  the 


xxviii  INTRODUCTORY 

insulation  of  their  connections.  Temperament  may  have 
befriended  me,  but  the  germ  of  carefulness  was  implanted 
by  Mr.  Finlay,  and  I  am  grateful  to  him  for  it. 

The  article  from  which  I  have  quoted  attracted  the 
notice  of  Dr.  Stone  of  St.  Thomas's,  a  correspondence 
resulted,  and,  eventually,  I  collaborated,  unofficially,  with 
him  in  the  preparation  of  his  Lumleian  lecture  of  the  year, 
the  subject  being,  "  The  Human  Body  Considered  as  an 
Electrolyte." 

At  that  time  I  am  afraid  we,  neither  of  us,  knew  very 
much  about  it,  but  although  working  in  different  sections 
of  the  field  of  scientific  investigation,  we  had  both  arrived 
at  one  conclusion,  viz.,  that  local  pyrexia  interfered  with 
local  insulation  resistance. 

The  importance  of  this  discovery  can  scarcely  be  over- 
estimated, but  we  did  not  realise  it ;  he,  not  before  his 
death,  which  occurred  not  long  after,  I,  not  for  many  years, 
because  other  occupations  and  duties  intervened  and 
research  work  had  to  be  relegated  for  the  nonce  to  the 
background. 

It  was  some  time  about  the  year  1900  that  I  fitted  up 
a  laboratory  and  seriously  took  up  my  task  anew.  And 
then  a  curious  thing  happened.  We  had  a  juvenile  party, 
and  some  of  the  young  people,  inspired,  perhaps,  by  a 
magazine  article  or  fairy-tale,  asked  me  if  apples  were 
electrical,  if  one  could  eat  things  which  would  make  one 
luminous,  and  so  forth.  I  replied,  "  Come  and  see." 
We  went  into  the  testing-room,  and  having  procured  some 
apples  and  oranges  and  lemons,  I  connected  two  steel 
darning-needles  by  two  lengths  of  flexible  wire  to  the 
terminals  of  the  galvanometer  and,  of  course,  obtained 
deflections.     These  experiments  were  regarded  by  me,  at 


INTRODUCTORY  xxix 

the  time,  as  "  parlour  tricks,"  and  in  making  them  I  had 
no  object  other  than  the  amusement  of  the  youngsters. 
But  when  upon  reversing  an  apple  I  obtained  a  reversal 
of  sign  my  interest  was  keenly  aroused  and  a  series  of 
experiments  was  initiated  which  are  described  in  Part  I, 
and  which,  so  far,  touch  little  more  than  the  fringe  of  the 
subject. 

From  that  time  I  went  on  working  patiently  between 
intervals  of  strenuous  commercial  and  professional  life, 
saying  nothing,  publishing  nothing,  but  collecting  data 
upon  which  to  found  a  considered  opinion — and  this  present 
volume  is  the  result. 

A.  E.  B. 


Part   I 

ELECTRICAL   STRUCTURE  AND 
FUNCTION      IN      PLANT      LIFE 


STUDIES  IN  ELECTRO-PHYSIOLOGY 


Chapter   I 
GENERAL 

It  has  long  been  known  that  the  application  of  electricity 
to  the  soil  is  sometimes  beneficial  to  plant  life,  and  some 
remarkable  results  in  the  direction  of  increasing  the 
quantity  and  quality  of  crops  have  been  in  that  way 
obtained.  But  hitherto  no  adequate  attempt  seems  to 
have  been  made  to  ascertain  if  Nature  has  endowed  the 
vegetable  world  with  any  system  by  means  of  which 
currents  of  electricity  can  be  utilised,  assimilated,  or 
stored. 

The  experiments,  therefore,  conducted  during  the  past 
thirty  or  more  years  have  not  been  altogether  conclusive, 
and  no  really  satisfactory  evidence  has  yet  been  obtained 
beyond  the  fact  that,  under  certain  conditions  and  in 
certain  circumstances,  electricity  is  favourable  to  growth. 

In  Structural  and  Physiological  Botany  by  Thom^, 
translated  by  Dr.  Alfred  W.  Bennett,  and  accepted  as  the 
recognised  text-book  in  the  technical  schools  of  Germany, 
there  occurs  the  following  passage  : — 

"  The  chemical  processes  within  the  cells  of  a  plant, 
the  molecular  movements  connected  with  growth,  and  the 
internal  changes  on  which  the  activity  of  the  protoplasm 
depends — whether  exhibited  in  the  formation  of  new  cells 

3  b2 


4  ELECTRICAL   STRUCTURE   AND 

or  in  motility — are  probably  connected  with  the  dis- 
turbance of  electrical  equilibrium.  The  fluids  of  different 
chemical  properties  in  adjoining  cells,  their  decomposition, 
the  evolution  of  oxygen  from  cells  containing  chlorophyll, 
the  formation  of  carbon  dioxide  in  growing  organs,  and 
the  process  of  transpiration — all  these  vital  processes  must 
produce  electrical  currents ;  although  this  fact  has  not  yet 
been  experimentally  determined  or  accurately  investigated."  * 

Two  of  the  greatest  authorities  upon  Vegetable 
Physiology  are,  or  were,  Sachs  and  Strasburger,  although 
equally  valuable  work  has  been  done  by  Vines  and  Green. 

Sachs,  in  his    twelfth  lecture,   said :     "  That  electro- 
motive mechanisms  are  present  in  the  normal  life  of  the 
plant  itself  may  be  in  part  directly  demonstrated,  in  part 
presumed  on  general  grounds.     It  has  been  established, 
for  instance,  that  every  movement  of  water  in  a  tissue, 
even  in  the  woody  mass,  is  connected  with  slight  electric 
disturbances ;     and   that   these   even   appear   when   dis- 
placements   of   water    are    caused   by   the   mere   passive 
bending  of  a  portion  of  a  plant,   or  by  movements  of 
irritability  on  its  part.     In  addition  we  may  assume  that 
the  chemical  processes  in  nutrition,  continually  going  on 
in  the  plant,  and  the  molecular  movements  during  growth 
and  the  passage  of  fluids  from  place  to  place,   are  all 
connected  with  electrical  disturbances  of  various  kinds, 
although  it  has  not  been  possible  to  demonstrate  this 
experimentally.     We    may    also    suppose    that    in    the 
ordinary  life  of  land-plants  especially,    during  the  con- 
tinually altering  differences  of  electrical  tension  between 
the   atmosphere   and   the   soil,    equalisations   take  place 
through  the  bodies  of  the  plants  themselves.     The  land- 
plant  rooted  in  the  soil  offers  a  large  surface  to  the  air  by 
means  of  its  branches,  and  the  roots  are  still  more  closely 
in  contact  with  the  moist  earth,  while  the  whole  plant  is 
♦  The  italics  are  mine. 


FUNCTION   IN   PLANT  LIFE  5 

filled  with  fluids  which  conduct  electricity  and  are  decom- 
posed by  currents.  Such  being  the  case,  it  can  scarcely 
be  otherwise  than  that  the  electrical  tensions  between  the 
atmosphere  and  the  earth  become  equalised  through  the 
plant  itself.  Whether  this  acts  favourably  on  the  processes 
of  vegetation,  however,  has  not  been  scientifically  in- 
vestigated, since  what  has  been  done  here  and  there  in  the 
way  of  experiments  in  this  sense  can  scarcely  lay  claim  to 
serious  notice." 

Strasburger — with  whom  must  be  associated  Drs. 
Schenck,  Noll,  and  Karsten — has  nothing  to  say  upon  the 
subject,  and  I  think  it  may  reasonably  be  assumed  that 
our  knowledge  of  vegetable  electro-physiology  is  summed 
up  in  the  extracts  I  have  given. 

The  analogies,  hovrever,  vvhich  exist  in  animal  and 
vegetable  physiology,  especially  in  the  lower  forms  of 
life,  are  sufficiently  full  of  interest  to  stimulate  further 
research  work.  That  locomotion  and  sensitiveness  are 
common  to  low  plants  as  well  as  to  low  animals,  that 
marked  similarity  exi&ts  between  the  animal  and  the 
vegetable  cell,  and  that  in  the  matters  of  the  presence  or 
absence  of  cellulose  and  the  nature  of  the  food  required  by 
both  organisms  there  does  not  appear  to  be  any  absolute 
point  of  distinction,  seemed  to  me  to  invite  investigation 
and  encouraged  me  to  undertake  it.  The  theory  of 
evolution,  enunciated  in  its  present  form  by  Darv/in  and 
by  Wallace,  regards  all  forms  of  life  as  having  a  common 
descent,  a  true  blood  relationship,  whence  arises  the 
impossibility  of  drawing  hard  and  fast  lines  of  separation ; 
and  my  own  results  are  in  perfect  harmony  Avith  this 
well-established  conclusion. 

We  know,  or  at  all  events  it  can  be  demonstrated,  that 
man  is  a  self-contained  neuro- electrically  controlled 
machine,  dependent  for  the  due  performance  of  his  func- 
tions upon  a  constant  supply  of  nerve-energy  at  a  low 


6  ELECTRICAL   STRUCTURE  AND 

potential ;  that  nerve-force  is  generated  in  the  body  with 
each  inspiration,  and  that  the  nerve-impulse  is  neuro- 
electrical  and  not  chemical.  If  that  is  so,  and  it  cannot 
successfully  be  disputed,  it  may  reasonably  be  assumed 
that  in  all  probability  electricity  plays  a  part  in  the 
vegetable  as  well  as  in  the  animal  world.  Investigation 
has  shown  the  soundness  of  this  theory,  as  I  hope  to  be 
able  to  prove,  and  further  research  at  the  hands  of  men 
more  capable  than  myself  may  lead  to  far-reaching 
consequences  in  the  direction  of  an  advancement  of  our 
knowledge  of  practical  horticulture  and  floriculture. 

Briefly,  the  conclusions  at  which  I  have  arrived  are  as 
follows  :■ — 

(1)  Everything    living,  whether  animal  or  vegetable, 

has  a  well-defined  electrical  system ;  the  non- 
living possessing  capacity  only  ;  and  that  only 
in  conjunction  with  moisture. 

(2)  Broadly  speaking,    the  edible    part  of  a  fruit  or 

vegetable  is  the  positive  element,  or  that  part 
which  yields  a  positive  galvanometric  reaction. 

(3)  Dry  earth    is  a  bad  conductor  of  electricity,  and 

therefore  water  is  required  as  an  electrolyte  as 
well  as  being  necessary  in  the  formation  of 
protoplasm,  etc. 

(4)  Every  tree,  shrub,   plant,  fruit,   vegetable,  tuber, 

and  seed  is  an  electrical  cell,  differing  from  cells 
made  by  human  agency  in  that  it  cannot  be 
polarised  or  discharged  so  long  as  it  remains 
structurally  perfect. 

(5)  The  skin,  peel,  rind,   or  jacket  of  fruits  and  vege- 

tables is  of  the  nature  of  an  insulating  substance 
primarily  designed  for  the  conservation  of  their 
electrical  energy. 

(6)  The  electro -motive  force  of  them  all  is  the  same ; 

the  current  varying  in  accordance  with  Ohm's 

Tj' 

law,  i.e.,  C  =  ^,  where  R  =  the  internal  resistance. 


FUNCTION  IN   PLANT  LIFE  7 

(7)  Plants  grown  in  pots  or  removed  from  the  earth 

and  placed  in  other  receptacles  differ  materially 
in  their  electrical  constitution  from  those  grown 
in  the  earth. 

(8)  If   a   suitable     electrolyte,    other   than     water,    is 

mixed  with  the  soil  it  is  possible  to  grow  plants 
with  much  less  moisture,  and 

(9)  Growth  may   be  stimulated   by  means   of  a   con- 

tinuous current  of  electricity  of  low  potential  and 
proper  sign. 

In  the  experiments  of  which  an  account  is  about  to  be 
given  the  recording  instrument  was  a  Kelvin  Astatic 
Reflecting  Galvanometer  (see  p.  235)  of  80,000  ohms 
resistance  at  15°  C,  and  a  sensibility  of  about  4,000  divisions 
of  the  scale,  at  a  metre  distance,  per  micro-ampere.  My 
chief  difficulty  was  in  the  selection  of  a  reliable  form  of 
electrode.  Those  of  the  non-polarisable  variety  were,  for 
reasons  into  which  I  need  not  presently  enter,  deemed 
unsuitable.  Needles  were  obviously  necessary.  Platinum 
was  shown  by  Oliver  Heaviside  in  1885  *  to  set  up  secon- 
dary action  even  in  distilled  water,  and  most  amalgams 
were  open  to  the  same  objection  as  well  as  to  the  suspicion 
of  want  of  homogeneity.  Finally,  steel  was  chosen  as  the 
metal,  and  the  electrodes  with  which  more  than  ten 
thousand  tests  were  taken  without  there  being  one  dis- 
cordant result  were  darning-needles  of  equal  gauge  con- 
nected to  flexible  wires  of  low  resistance.  That  there  are 
theoretical  objections  to  this  form  of  electrode  I  am  well 
aware,  but,  as  I  propose  to  prove,  they  cannot  be  upheld 
in  face  of  the  evidence  to  be  adduced. 

In  normal  conditions  of  weather  and  in  countries  free 
from  frequent  seismic  and  magnetic  disturbances,  the 
Earth  is  always  the  negative  and  the  Air  the  positive 
terminal  of  Nature's  electrical  system. 

*  Tha  Ekctrician. 


8  ELECTRICAL   STRUCTURE  AND 

Everything,  therefore,  that  grows  in  the  earth  is  charged 
by  the  earth  through  the  roots,  and  by  the  air  through  the 
flowers  and  leaves  (the  lungs,  as  it  were,  of  the  tree  or 
plant),  so  that  in  the  roots,  stem,  stalks,  and  veins  the 
tree,  shrub,  or  plant  has  its  negative  terminals,  while  those 
parts  of  the  leaves  between  the  veins  are  positive. 

Examination  of  the  vascular  bundles  and  laticiferous 
vessels  of  plants  will  make  this  clear. 

In  all  fruits  and  vegetables  the  negative  and  positive 
systems  are  plainly  discernible  once  the  eye  has  been 
taught  to  look  for  and  recognise  them. 

Before  going  into  detail,  hov/ever,  it  will  be  as  well  to 
consider  the  electrodes. 

I  found  that  when  two  wires  of  equal  gauge  and  length, 
soldered  to  two  steel  needles  of  exactly  the  same  gauge  and 
length,  were  connected  to  the  terminals  of  the  galvanometer 
and  the  needles  were  inserted  in  various  objects  and 
liquids,  certain  deflections  were  observed,  and  that  such 
deflections  were  not  momentary  but  constant. 

These  deflections  are  explained  as  being  due  to  galvanic 
actaon. 

There  are  two  theories,  i.e. — 

(1)  Two   metals — that   is   to    say,    one   needle   being 

electrically  positive  to  the  other — in  one  exciting 
liquid,  or 

(2)  One  metal  in  two  such  liquids. 

It  will,  however,  be  only  necessary  to  consider  the  first 
seriously. 

Let  us  suppose  that  we  are  using  tv>^o  wires  of  exactly 
equal  length  soldered  to  two  steel  needles  as  before  men- 
tioned, and  that  the  object  under  examination  is  an  apple. 
In  order  to  settle  which  is  the  positive  and  which  the 
negative  side  of  the  galvanometer  scale  from  its  central 
zero,  we  will  first  connect  the  positive  or  carbon  terminal  of 
a  dry  cell  to  the  right-hand  terminal,  and  the  negative  or 


FUNCTION   IN   PLANT  LIFE  9 

zinc  terminal  of  the  ceil  to  the  left-hand  terminal  of  the 
recording  instrument.  The  resultant  deflection  is  to  the 
right  of  zero,  and  we  may  therefore  call  the  right  side  of 
the  scale  from  zero  positive  and  the  left  side  from  zero 
negative. 

Now,  if  we  insert  the  needle  connected  to  the  right  side 
of  the  galvanometer  in  the  stalk  of  the  apple  and  the  other 
needle  in  the  flower  end,  we  get  a  constant  negative  deflec- 
tion. If  that  deflection  is  due  to  galvanic  or  chemical 
action,  then  so  long  as  we  do  not  alter  the  connections  upon 
the  galvanometer,  and  reasoning  upon  the  hypothesis  that 
the  right  needle  is  electrically  negative  to  the  left  needle 
and  that  chemical  action  is  set  up  by  their  contact  with  the 
malic  acid  of  the  apple,  the  deflection  must  continue  to  be 
negative  when  the  fruit  is  reversed  and  the  right  needle 
is  inserted  in  the  flower  end  and  the  left  needle  in  the  stalk. 
Also  the  signs  of  both  deflections  must  be  reversed  if  we 
reverse  the  wires  upon  the  terminals  of  the  galvanometer. 
But  it  is  not  so ;  nothing  of  the  kind  ever  occurs  or  can 
occur.  Every  fruit  will  give  a  constant  negative  deflection 
when  the  right-hand  needle  is  inserted  in  the  stalk,  and  a 
constant  ijositive  deflection  when  it  is  inserted  in  the 
flower  end ;  while  every  tree,  shrub,  plant,  vegetable,  and 
individual  leaf  will  yield  a  constant  negative  deflection 
when  the  right-hand  needle  is  connected  v.ith  root,  stalk, 
or  vein,  and  vice  versa.  The  wires  may  be  reversed  upon 
the  terminals  of  the  galvanometer  as  often  as  desired. 
There  will  be  no  difference  whatever  in  the  phenomena 
observed.  In  the  case  of  pot-grown  plants  and  fruits, 
etc.,  polarity  is  reversed  because  the  moist  soil  in  the  pot 
receives  its  charge  from  the  positive  air  instead  of  from 
the  negative  earth. 

If,  however,  diffusion  takes  place  by  reason  of  injury  or 
decay,  and  the  plant,  vegetable,  fruit,  or  leaf  becorues 
rotten,  no  reversal  of  sign  will  be  obtained. 


10  ELECTRICAL   STRUCTURE  AND 

The  Apple. 

Fig.  1  illustrates  the  electrical  structure  of  the  apple. 
The  stalk,  receiving  its  negative  charge  from  the  earth, 
communicates  directly  with  the  negative  core,  which,  as 
will  be  seen,  is  insulated  from  the  positive  or  edible  portion. 
The  core  terminates  at  its  upper  end,  it  will  be  observed, 
in  a  dry  plug — ^the  remains  of  the  flower — while  the  stalk 
is  always  sealed,  either  by  dry  fibre  or  by  a  gummy  or 
resinous  secretion.  The  rind  or  outer  covering  is  of 
enormous  resistance,  and  is  evidently  designed  to  conserve 
the  energy  of  the  cell  by  giving  it  high  absolute  insulation. 

From  Fig.  2  we  gather  some  idea  of  the  means  adopted 
by  Nature  to  prolong  life. 

In  the  example  shown,  seven  days  had  elapsed  since 
the  division  was  made,  the  surfaces  had  partially  dried, 
probably  to  increase  their  resistance  and  lessen  liability 
to  evaporation,  the  walls  of  the  core  had  similarly  har- 
dened, and  the  rind  or  peel  had  closed  round  the  edges  to, 
we  may  assume,  prevent  the  loss  of  any  of  the  juice 
necessary  to  the  apple's  continued  electrical  activity. 

The  pear  and  the  quince  so  nearly  resemble  the  apple 
that  it  is  unnecessary  to  describe  them.  The  only  difference 
is  that  the  core  is  more  elongated  in  shape  and  is  placed 
at  a  slightly  greater  distance  from  the  stalk  than  in  the 
case  of  the  apple. 

The  Banana. 

It  will  be  seen  that  the  negative  terminal — the  stalk — 
is  connected  with  the  skin  and  an  inner  lining  from  which 
the  positive  flesh  of  the  fruit  is  instantly  detachable.  No- 
where does  there  appear  to  be  any  actual  electrical  contact 
between  the  negative  and  positive  systems  except,  pos- 
sibly, by  osmosis — the  flesh  being  enclosed  in  an  envelope — 
and  as  the  whole  of  the  flesh  is  positive  the  dietetic  value 


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FUNCTION   IN  PLANT  LIFE  11 

of  this  fruit  should  be  high.  Unfortunately  it  has  when 
ripe,  and  probably  owing  to  its  porous  skin,  a  compara- 
tively low  insulation  resistance  and  therefore  a  short  life. 
Figs.  3  and  4  will  serve  to  illustrate  the  points  mentioned. 

The  Tomato. 

The  tomato  (Fig.  5)  affords  us  convincing  testimony  of 
the  reliability  of  our  electrodes,  because  during  the  late 
summer  we  can  take  one  grown  in  the  open  ground  and 
one  from  the  greenhouse  and  test  them  under  exactly  the 
same  conditions  and  at  the  same  time.  That  grown  in  the 
open  ground  will  be  found  to  be  negative  at  the  stalk  and 
positive  where  the  flower  originally  appeared,  while  that 
from  the  greenhouse,  Avhere  it  had  been  deprived  of  its 


supply  of  current  from  the  negative  earth  and  compelled 
to  take  its  root-charge  from  the  positive  air,  assumes  an 
opposite  polarity  and  is  positive  at  the  stalk  end,  etc. 
These  remarks  apply  to  all  fruits  and  vegetables  cultivated 
alike  in  the  garden  and  in  pots  in  the  greenhouse,  such  as 
the  cucumber,  the  orange,  lemon,  etc.,  etc. 

But  if  the  soil  in  the  pot  is  connected  by  a  metallic 
conductor  with  the  earth  {see  illustration),  no  change  of 
polarity  will  occur. 


12  ELECTRICAL   STRUCTURE   AND 

The  Orange,  Lemon,  Grape-Fruit,  etc. 

In  testing  these  fruits  great  care  has  to  be  exercised 
ov/ing  to  the  large  quantity  of  juice  they  contain,  the 
rapidity  of  its  action  upon  steel,  the  danger  of  diffusion, 
and  the  extreme  delicacy  of  cells  of  which  the  fruits  are 
mainly  composed  and  the  narrow  contacts  they  offer. 
Their  structure,  electrically  considered,  is  best  explained 
by  Figs.  6,  7,  and  8,  but  especial  notice  should  be  taken  of 
the  wonderful  manner  (shown  in  the  sectional  plans)  in 
which  the  positive  flesh  of  the  fruit  is  surrounded  by 
protective  material,  and  how  that  protective  material  is 
connected  in  turn  with  the  central  and  outer  negative 
system.  Nor  is  their  absolute  insulation  provided  for  in 
a  less  remarkable  manner.  The  skins  of  the  orange  and 
lemon  in  particular  appear  to  be  porous,  but  in  reality 
they  are  built  up  of  innumerable  cells  containing  a  highly- 
resistant  ethereal  oil  which,  until  expelled  by  evaporation, 
conserves  their  energy. 

The  Turnip 
(Swede  and  Mangel -Wurz el,  etc.) 

In  Fig.  9  it  will  be  seen  that  the  negative  system  of  this 
vegetable  extends  from  the  root  along  the  outer  perimeter 
and  to  the  whole  of  the  thickness  of  the  rind.  The  inner 
lining  of  this — an  envelope,  as  it  were — is  probably  pro- 
tective material,  and,  so  far  as  I  am  able  to  judge,  the 
whole  of  the  interior  is  positive  ;  that  system  extending  to 
the  positive  terminal,  or  flower  end  ;  and  to  those  portions 
of  the  foliage  free  from  stalks  and  veins  which  connect 
directly  with  the  negative  system.. 

From  an  electrical  point  of  view  the  turnip  compares 
unfavourably  with  many  other  vegetables.     At  no  time 


■*. 

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FUNCTION   IN   PLANT  LIFE  18 

is  its  skin  or  rind  of  very  high  resistance,  and  when  a 
turnip  is  divided — as  in  the  illustration  given — it  soon, 
especially  if  kept  in  a  dry  place,  becomes  unfit  for  food. 
L^nlike  some  other  vegetables,  such  as  the  potato,  it  does 
not  appear  to  be  provided  with  the  means  of  forming  fresh 
insulating  material  upon  the  cut  surface,  with  the  result 
that  it  dries  up,  and,  not  being  able  for  that  reason  to 
absorb  charge  from  the  air,  loses  its  electrical  activity  and 
degenerates  into  a  spongy,  fibrous,  and  inedible  mass.  If, 
however,  it  is  kept  in  a  moist  condition  it  retains  capacity, 
or  power  of  absorption  of  electricity  from  the  air,  and  can 
be  preserved  for  a  longer  period  of  time.  This  was  ascer- 
tained by  cutting  turnips  in  halves.  Figs.  10  and  11  show 
the  halves  of  two  tm^nips  taken  from  the  same  bunch.  That 
given  in  elevation  was  kept  under  water  for  ten  minutes 
three  times  daily,  while  the  other  (sectional  plan)  was  left 
untouched  ;  both  being  subjected  to  identical  atmospheric 
conditions.  In  the  same  figures  we  have  the  two  halves 
of  the  turnip  in  elevation.  These  were  treated  as  above, 
and  in  both  instances  were  sketched  after  an  interval 
of  eight  days.  They  call  for  no  further  comment  from 
me. 


The  Carrot  and  Parsnip. 

Fig.  12  sufficiently  illustrates  the  electrical  structure  of 
these  vegetables,  but  attention  may  be  drawn  to  the  fact 
that  the  roots  are  connected  directly  with  the  negative, 
and  that  the  central  positive  system  is  insulated  or  pro- 
tected from  the  former  in  the  manner  shown.  If  these 
vegetables  are  divided  in  the  middle,  lengthwise,  the 
negative  can  be  separated  from  the  positive  portion  with 
the  fingers,  leaving  the  latter  exposed  as  a  tongue  and 
exhibiting  the  former  encircled  by  root-filaments. 


14  ELECTRICAL   STRUCTURE  AND 

The  Onion. 

This  is  an  unusually  difficult  vegetable  to  test,  in  that 
while  the  bulb  appears  to  form  a  complex  cell,  the  inter- 
mediate contact-spaces  are  so  narrow  and  the  liability  to 
diffusion  so  great,  when  the  onion  is  divided,  that  I  am 
unable  to  speak  with  certainty.  Botanists,  however,  will 
readily  solve  the  problem,  which,  from  an  electrical  stand- 
point, is  to  differentiate  the  layers  connected  with  the  root 
from  those  in  alignment  with  the  tubular  leaves.  The 
former  will  be  negative  and  the  latter  positive. 

Fig.  18  depicts  the  structure  of  the  onion  as  it  is  pre- 
sented to  the  unaided  eye  and  in  so  far  as  I  am  able  to 
determine  it  galvanometrically.  The  negative  system 
seems  to  extend  from  the  root  to  the  outer  second  and 
third  layers  of  the  bulb,  between  which  and  the  central 
positive  system  there  exists  a  membranous  and  probably 
protective  lining.  The  contacts  afforded  by  the  poles  are 
well  defined,  the  absolute  insulation  is  extraordinarily  high, 
and  altogether  the  onion  is  a  vegetable  cell  of  a  very 
perfect  description.  Its  electro-motive  force  is,  ap- 
proximately, 0-086  volt ;  the  current  varying,  of  course, 
with  size.  Such  a  cell  is  invaluable  in  the  testing-room 
for  such  work  as,  for  instance,  taking  the  constant  of  a 
sensitive  galvanometer  or  comparing  deflections  from 
living  muscle  or  tissue,  instead  of  using  for  the  purpose  a 
standard  cell  liable  to  polarisation  when  employed  without 
very  high  resistance  in  circuit. 

TUBERS. 

These  differ  in  their  electrical  constitution  from  root- 
vegetables  proper  and  from  fruits,  in  that  they  are  not 
merely  bipolar,  but  have  a  number  of  positive  and  negative 
terminals.  I  have  taken  two  examples,  i.e.,  the  potato 
and  the  Jerusalem  artichoke,  reserving  others  for  future 
%vestigation. 


^ 


FUNCTION  IN   PLANT  LIFE  15 

The  Potato. 

The  potato  plant  receives  its  supply  of  current  direct 
from  the  earth,  but  it  is  open  to  doubt  whether  such  is  the 
case  with  the  tubers  to  which  it  gives  birth.  They  are 
connected  with  the  parent  plant  by  a  filament  or  filaments 
— not  altogether  unlike  the  umbilical  cord  of  the  human — 
through  which  or  by  means  of  which  they  are  energised. 
In  the  potato  shown  in  Fig.  14  I  can  trace  only  two  eyes 
to  which  such  filaments  might  have  been  attached  (marked 
a  and  b).  They  are  negative  terminals  communicating 
with  the  outer  negative  system,  while  c,  d,  and  e  are 
terminals  (positive)  of  the  lines  /,  g,  and  h.  It  is  only 
when  these  slightly  darker  lines  reach  the  jacket  that  we 
find  a  live  or  prolific  eye.  The  unprolific  eyes,  so  called, 
are  those  by  which  the  tuber  is  attached  by  a  filament  or 
filaments  to  the  parent  root. 

It  has  been  seen  that  some  fruits  seek  to  protect 
themselves  when  cut  or  injured,  or  rather  that  Nature  has 
made  in  that  regard  some  provision  for  them. 

In  this  respect  the  potato  is  well  endowed.  Very 
shortly  after  being  cut  it  exudes  a  starchy  substance  which 
dries  rapidly,  and  forming  a  film  over  the  cut  surface, 
restores  in  some  measure,  if  not  entirely,  the  impaired 
insulation,  as  well  as  preventing  loss,  by  evaporation,  of  the 
fluid,  without  which  it  must  become  electrically  dead. 
This  tuber  will,  in  fact,  keep  longer  and  grow  better  after 
being  injured  than  any  other  member  of  the  vegetable 
world  with  which  I  am  acquainted,  other  things  being 
equal. 

The  Jerusalem  Artichoke. 

There  are  several  points  of  difference  between  this  tuber 
(Figs.  16  and  17)  and  the  potato.  It  is  covered  with  root- 
filaments,  is  distinctly  bipolar  as  regards  the  ends,  and  docs 


16  ELECTRICAL   STRUCTURE  AND 

not  appear  to  be  provided  with  so  efficient  a  repair  outfit. 
In  common  with  the  potato,  it  has  a  marginal  negative 
system  and  several  positive  terminals,  but  I  should  imagine, 
from  the  number  of  root-filaments,  that  instead  of  being 
dependent  upon  the  mother -plant  it  derives  its  electrical 
supply  directly  from  the  earth. 

LEAVES. 

I  selected  a  few  examples  from  evergreen  and  deciduous 
leaves  with  a  viev/  to  seeing  what  difference,  if  any, 
existed  between  them  as  regards  relative  conductivity,  the 
ramifications  of  their  negative  systems,  and  the  quality  of 
the  main  conductors — the  stalks — through  which  current 
is  conveyed  to  them  from  the  earth. 

As  a  rule,  in  deciduous  leaves  the  veins  do  not  seem  to 
me  to  form  so  complete  and  extensive  a  network  as  in 
those  of  the  evergreen  variety.  They  are,  moreover,  not 
so  well  insulated,  are  thinner  in  texture,  and,  if  they  lose 
their  moisture  under  the  influence  of  prolonged  summer 
heat,  become  electrically  inert  and  fall.  Such  a  leaf  is 
that  of  the  horse-chestnut  (Fig.  18),  and  it  offers  a  sharp 
contrast  to  that  of  the  ivy  (Fig.  19),  in  which  the  negative 
veins  form  an  almost  complete  network,  and  which  carries 
three  principal  veins  as  against  the  single  one  of  the  horse- 
chestnut.  The  leaf  is  also  more  substantial,  is  infinitely 
better  adapted  to  retain  its  moisture,  and  therefore  its 
conductivity  and  capacity  of  electrical  absorption,  v/hile 
the  walls  of  the  veins  appear  to  possess  high  resistance, 
or,  in  other  words,  a  high  degree  of  insulation  ;  the  inter- 
mediate or  positive  parts  of  the  leaf  being  able  in  the 
presence  of  occasional  rain  or  even  a  damp  atmosphere  to 
receive  positive  charge  from  the  air. 

This  perfection  of  insulation  and  inherent  interior 
moisture  extend  to  the  stems  of  the  plant,  so  that,  their 


FUNCTION  IN   PLANT  LIFE  17 

internal  resistance  being  unusually  low,  a  current  in  excess 
of  the  average  is  carried  by  them,  and  may  possibly  ex- 
plain, in  some  measure,  the  ivy's  tenacious  hold  upon  life. 
The  insulation  is  probably  due  to  the  numerous  resin- 
passages  found  in  the  plant. 

Do  Vegetables  and  Fruits  possess  Capacity  ? 

The  answer  to  this  question,  so  far  as  the  experiments 
have  gone,  is  in  the  affirmative.  No  attempt  has  been 
made  to  determine,  by  comparison  with  a  standard  con- 
denser, the  electrostatic  capacity  of  any  vegetable  or  fruit, 
as  the  conditions  would  vary  enormously  with  size,  degree 
of  moisture  present,  and  insulation  resistance,  without 
offering  adequate  compensation  for  the  labour  involved. 

It  was  therefore  thought  sufficient  to  ascertain  if  fruits 
and  vegetables  when  put  in  circuit  with  a  battery  and  a 
recording  instrument,  merely,  by  reason  of  their  conducting 
juices,  formed  part  of  a  simple  circuit,  or  whether  after  the 
battery  had  been  disconnected  they  retained  charge : 
whether  by  reversing  the  polarity  of  the  battery  the 
polarity  of  the  object  under  examination  could  be  altered, 
and  for  how  long  any  such  charge  or  change,  if  any,  was 
observable. 

The  first  experiment  was  with  a  quince.  With  the 
right-hand  needle  inserted  in  the  stalk  and  the  left  needle 
in  the  flower  end  it  gave  a  constant  negative  deflection. 
The  needles  were  allowed  to  remain  in  the  fruit,  but  the 
wires  to  which  they  were  attached  were  connected  to  a  dry 
cell  for  five  minutes,  i.e.,  right  needle  to  carbon  and  left 
needle  to  zinc.  The  resultant  deflection  was  strongly 
positive,  discharge  took  place  slowly,  and  it  was  a  consider- 
able time — unfortunately  not  recorded — before  the  original 
negative  deflection  was  restored. 

At  a  later    date  I   tested   a    number   of  fruits   and 

c 


18 


ELECTRICAL   STRUCTURE  AND 


vegetables,     using     a    reflecting    galvanometer     of    the 
D'Arsonval  feype. 

In  every  case  the  connections  were  as  shown  by  Fig.  21a, 
the  needles,  except  where  otherv/ise  mentioned,  being  left 
in  the  object  under  examination  during. the  whole  of  the 
test.  The  scale  limit  was  250  mm.  from  a  central  zero. 
In  every  case,  also,  the  fruit  or  vegetable  gave,  with  the 


Fig.  21  A. — Connections  in  Capacity  Tests. 

a;  =  vegetable  cell. 

a  »=  positive  terminal  of  same. 

6  =  negative      „  „       „ 

c=dry  cell  1'5  volts. 

d= plug  switch. 

G  =  galvanometer. 

right  needle  inserted  in  the  stalk  end,  a  constant  off-scale 
negative  deflection. 

It  is  not  proposed  to  give  full  details,  as  they  might 
become  wearisome,  but  to  summarise  the  results  obtained 
in  each  test  or  series  of  tests. 


The  Onion. 

With  the  right  needle  to  the  root  and  the  left  needle 
to  the  foliage  end  it  gave  a  constant,  fairly  rapid,  off-scale 
negative  deflection.  Five  minutes'  charge  from  a  cell  of 
1-5  volts — ^positive  to  root  and  negative  to  foliage — merely 


FUNCTION  IN  PLANT  LIFE  19 

reduced  this  deflection,  and  it  was  necessary  to  give  a 
further  five  minutes'  charge.  At  the  end  of  this  time  it 
went  rapidly  off-scale  positive  and  remained  off-scale  for 
fifteen  minutes.  The  connections  were  then  earthed  for 
five  minutes  through  5,000  ohms,  when  the  charge  was 
found  to  be  dissipated  and  the  true  polarity  restored. 

In  a  second  experiment  with  the  same  onion  a  further 
ten  minutes'  charge  vv'as  not  fully  discharged  until  forty 
minutes  after  the  first  reading. 

A  Stick  of  Rhubarb. 

This  was  charged  for  five  minutes  and  the  cell  dis- 
connected. The  deflection  was  then  off-scale  positive. 
Five  minutes  later  it  had  fallen  to  160  mm.  positive,  and 
at  the  end  of  the  tenth  minute  risen  to  180  mm.  As  this 
might  have  been  due  to  the  effect  of  the  juice  upon  the 
electrodes,  these  were  removed,  cleaned,  and  carefully 
reinserted,  when  D  =  180  mm.  positive,  rising  in  a  fmlher 
five  minutes  to  250  mm.  Five  minutes  E,  however, 
removed  the  charge  and  the  original  polarity  returned. 

The  Apple. 

This  fruit  was  large,  ripe,  and  in  perfect  condition,  and 
exhibited  an  unusual  quantity  of  current.  Ten  minutes' 
charge  with  1-5  volts  merely  reduced  the  deflection  to 
50  mm.  negative.  1  therefore  gave  it  another  five 
minutes,  when  D  =  rapidly  off-scale  positive.  Ten 
minutes  later — it  being  still  off-scale — the  connections 
were  put  to  E  for  five  minutes  and  the  electrodes  rem.oved 
and  cleaned.  D  was  then  250  mm.  positive  and  five 
minutes  later  235  mm.  positive.  It  had  then,  unfortu- 
nately, to  be  left — insulated — until  the  next  day,  when  it 
had  fully  recovered. 


20  ELECTRICAL  STRUCTURE  AND 

The  Banana. 

This  was  really  a  small  plantain,  about  7  in.  long. 
After  ten  minutes'  charge  D  =  rapidly  off-scale  positive ; 
five  minutes  later  it  was  190  mm.  positive,  and  in  twelve 
minutes  thirty-five  seconds  more  had  gone  off- scale 
negative,  that  is  to  say,  had  fallen  440  mm.  It 
did  not,  however,  quite  regain  its  original  polarity  until 
it  had  been  short-circuited  through  5,000  ohms  for  a  further 
twenty  minutes.  Even  so  it  discharged  itself  in  twenty- 
eight  minutes  as  against  forty -one  minutes  of  the  onion, 
and  this  I  attribute  to  its  comparatively  low  absolute 
insulation  resistance. 

The  Turnip. 

I  took  two  examples  of  this  vegetable.  The  first  was 
oval  in  shape,  weighed  3  oz.,  and  had  been  kept  in  a  dry 
room  for  a  week,  both  poles  being  dry  and  fibrous.  The 
second  was  an  almost  perfect  sphere,  10^  in.  in  circum- 
ference, weighed  10  oz.,  and  had  been  recently  pulled. 
The  root  was  not  dry,  the  foliage  end  white  and  exuding 
moisture.  No.  1  was  charged  for  ten  minutes  as  before, 
when  D  =  very  rapid  off-scale  positive.  Short-circuited 
through  5,000  ohms  it  remained  off-scale  for  thirty-two 
minutes,  and  did  not  regain  its  former  polarity  for  thirty- 
three  minutes  more,  showing  a  slow  discharge,  but  one, 
after  allowing  for  higher  insulation,  not  inharmonious  with 
the  preceding  data.  Upon  examination  the  right  needle 
was  found  to  be  blackened  by  electrolysis  ;  the  left  needle 
having  traces  only. 

No.  2.  Ten  minutes'  charge,  as  before. — Immediate 
D  =  very  rapidly  off-scale  positive.  In  three  minutes  the 
light  returned  to  250  mm.  positive,  and  in  six  minutes 
more  had  gone  off-scale  negative  ;  the  vegetable  recovering 


FUNCTION  IN   PLANT   LIFE  21 

polarity  almost  instantly.  The  right  needle  was  quite 
blackened  and  the  left  needle  clean.  As  this  discordant 
result  might  have  been  due  to  leakage  through  the  moist 
poles  or  terminals  of  the  vegetable,  I  painted  both  with 
a  non-conducting  solution  and  allowed  it  to  dry,  in  order 
to  see  if  higher  insulation  would  slow  down  the  rate  of 
discharge. 

The  experiment  with  No.  2  was  then  repeated  under  the 
same  conditions  but  with  fresh  points  of  contact. 

After  ten  minutes'  charge  D  =  very  rapid  off -scale 
positive.  The  vegetable  then  remained  short-circuited 
through  5,000  ohms.  D  continued  off -scale  for  seventeen 
minutes,  when  the  vegetable  was  accidentally  knocked  over. 

No.  2  (third  experiment). — The  connections  were  put 
to  earth  until  the  vegetable  regained  polarity  and  gave 
perfect  reversals.  It  was  then  charged  for  ten  minutes 
with  1*5  volts,  when  D  =  very  rapid  off-scale  positive,  not 
falling  to  250  mm.  positive  until  sixteen  minutes  later. 
The  period  of  fall  from  250  mm.  positive  to  250  mm. 
negative  was  eight  minutes,  and  ten  minutes  later  the 
vegetable  had  recovered.  The  conclusion,  or  one  con- 
clusion, to  be  drawn  is,  of  course,  that  absolute  insulation 
is  a  factor  of  primary  importance  in  retention  of  charge. 

The  Orange. 

Circumference  8|  in.,  weight  5^  oz.  After  ten  minutes' 
charge  D  =  fairly  rapid  off-scale  positive.  In  ten  minutes 
it  fell  to  250  mm.  positive,  and  in  fifteen  minutes  more  the 
light  had  reached  250  mm.  negative  ;  the  fruit  regaining 
its  former  full  polarity  fifteen  minutes  later.  The  right 
electrode  showed  a  mere  trace  of  electrolysis.  The  charge 
in  this  case  remained  on  the  positive  side  of  the  scale  for 
nineteen  minutes,  but  the  absolute  insulation  of  the  orange 
and  lemon  is  not  very  high. 


22  ELECTRICAL   STRUCTURE   AND 


Chapter  II 

SOME   SEEDS   IN  THEIR  ELECTRICAL  ASPECT 

So  far  I  have  not  been  able  to  find  time  to  study  the 
electrical  problems  presented  by  germination,  but  I  am 
convinced  that  when  this  is  done  even  greater  proofs  of 
the  universality  of  the  law  will  be  forthcoming.  The 
subject  is  a  sufficiently  vast  one  to  call  for  more  than  the 
labours  of  one  man  and  the  compilation  of  one  book,  but, 
so  far  as  I  am  concerned,  it  must  be  reserved  for  future 
investigation. 

The  examination  of  seeds  in  their  various  stages  of 
development  present  features  of  interest  which  cannot  fail 
to  claim  the  attention  of  the  student,  and  although  my 
opportunities  for  observation  have  been  limited  by  a 
variety  of  circumstances,  I  am  glad  to  be  able  to  offer  some 
food  for  thought  and,  I  hope,  additional  stimulus  to 
research. 

During  our  consideration  of  the  nature  of  the  nervous 
impulse  we,  or  at  all  events  some  of  us,  learn  that  in  the 
case  of  the  hum.an  fcetus  independent  existence  is  only 
begun  when  air  (oxygen)  is  first  taken  into  the  lungs  and 
complete  circulation  established — until  that  moment  the 
child  is  dependent  upon  the  maternal  blood-stream — and 
will  note,  in  the  chapter  upon  Cell -reproduction,  that  the 
so-called  "  resting  "  stage  of  a  cell  is  really  a  developing 
stage.  That  being  so,  it  follows,  I  think,  logically,  that 
while  a  seed  is  still  attached  to  the  parent  plant  or  tree  it 
is  equally  dependent  with  the  unborn  child,  and  that  the 


FUNCTION  IN   PLANT  LIFE 


23 


same  law  which  governs  cell -division  should  guard  the 
immature  seed  from  the  possibility  of  premature  germina- 
tion by  withholding  from  it  a  perfected  electrical  system. 
Unless  that  is  so  there  is  a  flaw  in  our  reasoning,  or  our 
understanding  of  the  law  is  at  fault. 

The  Horse-Chestnut. 

At  the  time  of  year  of  the  experiments  about  to  be 
described  (September)  and  for  the  following  few  weeks 
the  seeds  were  in  various  stages  of  development,  and  could 
be  studied  at  leisure.  The  method  adopted  v/as  to 
cut  the  pods  in  halves  longitudinally  and  test  them  gal- 
vanometrically,  to  ascertain  the  relative  sign  and  electrical 
activity  of  their  various  parts.  The  following  photo- 
graphs are  illustrative  of  the  result : — 


^A'e^ative  ttrminai 


J^asifc'ue     CZ 


J^onennsalatiTip  rntmbrane  O 

Condurtirr^  layer ^ 

Outer miulatinj membrane   a 


jro3itLOe  Ct 


Almost  Aledncallu  neutral 
c.  e  vfru  uieaK  +eieclri/l/atiOrt .  & 


Ouienuasulationf 


Fig.  22. — Section  of>^orse-Chestnut.  ;  [Original,  photo.] 

a,  a,  part,  consisting  of  white,  pithy  substance,  which  is  positively 
charged  ;  &,  insulating  membrane  immediately  enveloping  the  seed 
substance  ;  c,  conducting  layer,  negatively  charged  ;  d,  insulating  mem- 
brane enveloping  the  conducting  layer  ;  e,  seed  substance  yielding  only  a 
few  millimetres  positive  deflection  as  against  the  1,000  mm.  negative  of 
the  conducting  layer  ;  /,  outer  insulation,  porous,  and  of  low  resistance. 


The  next  photograph  shows  the  negative  terminal  and 
system  more  clearly,  and  gives  a  better  idea  of  the  extent 
of  the  positively  charged  material.     This  seed  is  not  in 


24 


ELECTRICAL   STRUCTURE  AND 


such  an  advanced  stage  of  development  as  the  preceding 
one,  and  the  pod  contained  two  seeds. 


.jye^afiue  terminal 


Fig.  23. — Section  op  Horse-Chestnut.     [Original photo.'] 

Two  insulating  membranes  are  shown,  but  there  is  a 
third,  not  adherent  to  the  seed,  but  lining  the  cavity  in 
which  it  lies,  and  designed,  there  can  be  little  doubt,  to 
prevent  a  positive  charge  from  reaching  the  immature 
seed  ;  inasmuch  as  this  membrane  appears  to  be  formed 
before  the  membrane  d  attains  the  required  resistance. 
The  function  of  the  other  two  membranes,  b  and  d,  en- 
closing the  actively  charged  conducting  layer,  c,  calls  for 
more  elaborate  if  hypothetical  explanation. 

Apart  from  the  seed  itself  the  major  portion  of  the  pod 
is  taken  up  by  a  white,  pithy  substance  of  positive  sign ; 
probably  charged  by  the  air  through  the  epidermal  spines 
or  pores.  While  the  seed  is  growing  it  does  not,  I  imagine, 
require  direct,  but  rather  modified,  electrical  stimulus. 
From  the  seed  substance  itself  I  obtained  deflections  of  a 
few  millimetres  only,  whereas  the  conducting  layer,  c,  gave 
excursions  of  one  thousand  and  over.  Assuming,  then, 
that  for  some  wise  purpose — possibly  to  give  adequate 
time  for  development — stimulus  to  the  seed  substance  is 
modified,  the  function  of  the  conducting  layer,  c,  becomes 
apparent,  inasmuch  as  it  would  play  much  the  same  part 


FUNCTION  IN   PLANT   LIFE  25 

as  the  lymph  space  on  a  nerve-fibre  or  the  copper  taping  on 
an  insulated  wire  in  preventing  an  induced  charge  from 
passing  it. 

Now  the  part  a,  a  is  positively  charged  by  the  air  and 
has  greater  surface  area  than  the  conducting  layer  c. 
We  should  therefore  find — as  we  do  find — that  the  tension 
of  c  is  in  excess  of  that  of  a,  a,  and  that  the  sign  is  negative 
instead  of  positive. 

That  is  while  the  seed  is  still  attached  to  the  tree  and 
has  no  separate  and  independent  existence. 

But  in  course  of  time  the  pod  falls  and  releases  the  seed 
by  splitting  segmentally.  The  latter  we  must  suppose  to 
be  planted  or  buried  in  the  soil  and  to  be  thereafter  depen- 
dent upon  the  earth,  as  man  is  mainly  dependent  upon  the 
air  as  the  source  of  electrical  energy.  Obviously,  then, 
some  change  must  take  place  to  enable  the  seed  to  survive, 
and  that  change  is  a  very  important  one.  The  conducting 
layer,  c,  dries  up,  and  therefore  ceases  to  intercept  charge, 
but  the  outer  membrane,  d,  after  contact  with  the  damp 
soil,  would  become  a  conductor,  and  without  the  inner 
membrane,  b,  no  electrical  system  could  obtain.  But  with 
d  as  a  conductor  and  b  as  the  insulating  material,  induction 
could  take  place,  and  the  seed  substance  receive  a  positive 
induced  charge  in  the  following  manner — 


rzyarM  charge 


Jffembrane  d,.  conductor 

„  6. .  nonconafuctor 

^eed 3ubifance :  conductor 

Fig.  24. 

so  that  the  two  membranes  are  necessary  both  while  the 
seed  is  in  the  pod  and  after  it  has  been  released. 

Fig.  25  shows  the  final  appearance  of  the  membranes 


26 


ELECTRICAL   STRUCTURE  AND 


d  and  b.  It  is,  however,  not  improbable  that  instead  of  the 
whole  of  d  becoming  conductive,  only  the  part  g  illustrated 
by  Fig.  25  may  so  function.  This  is  suggested  by  the 
greater  desiccated  space  between  the  membranes  at  that 
point.  But  even  in  that  event  the  only  material  differ- 
ence, so  far  as  I  can  see,  would  be  that  the  tension  of 
e  would  be  lower  than  that  of  d  by  reason  of  the  larger 
surface  area  of  e. 

Prior  to  the  completion  of  the  insulating  system  the 
conducting  layer  c  seems  to  receive 
charge  directly  through  the  stalk  of 
the  pod.  During  such  time,  there- 
fore, the  part  g,  or  the  depression 
marked  h  thereon  (Fig.  26),  would 
probably  be  the  point  of  contact. 

As  regards  the  unusually  elabo- 
rate insulation  of  the  pod  and 
seed  of  the  horse-chestnut,  it  is 
worthy  of  remark  that  the  secretion 
both  of  the  white,  pithy  material 
and  the  seed  substance  is  markedly  acid,  staining  steel  and 
instantly  turning  litmus-paper  red.     Neither  of  the  three 


/^artj 


Fig,  25. — Section  of 
Horse-Chestnut    Seed. 

Showing  the  final  ap- 
pearance of  the  mem- 
branes d  and  b. 

[Original  photo.] 


Fig.  26. — Horse-Chestnut  Seed.        [Original  photo.] 

Tlie  part  g  occupies  about  one-third  of  the  area  of  the  membrane  d  f 
h  is  a  small  circular  depression  upon  g  and  is  probably  of  the  nature  of 
a  contact  before  the  insulation  is  completed. 


membranes,  however,  has  any  effect  upon  litmus-paper, 
and,  so  far  as  I  could  determine,  all  are,  as  one  would  expect, 
chemically  neutral. 


FUNCTION  IN   PLANT  LIFE  27 

Fig.  27  gives  another  view  of  the  dried-up  layer,  c, 
and  shows  a  tongue-like  projection  of  the  seed  substance 


Transver^eSection 


fi 


/Seclion  at  /£_ 


Fig.  27. — Sections  of  Horse-Chestnut  Seed. 

[Original  photo.] 

Showing  projection  of  seed  substance. 
This  tongue-like  projection,  J:,  does    not  connect   with  h,   nor  is  it  so 
pointed  as  in  the  edible  chestnut ;    more  frequently  it  resembles  the  end 
of  a  dumb-bell  v.-hen  cut  in  section  transversely.     The  part  g  is  assumed, 
in  this  instance,  to  be  the  bottom  of  the  seed. 

similar  to  that  of  the  edible  chestnut  and  insulated  by  the 
inner  membrane  b  in  the  same  manner.  The  probable 
purpose  of  this  is  suggested  later  on. 

A  Contrast. 
I  had  before  me,  uncut,  an  edible  and  a  horse-chestnut, 
both  in  pod.  They  were  free  from  spines,  were  of  the 
same  colour,  size,  and  shape,  and  there  was  nothing  in 
their  outward  appearance  to  differentiate  them,  except 
that  upon  one  the  stalk  still  remained,  to  remind  me  that 
it  was  the  horse-chestnut.  I  cut  the  latter  in  halves,  as 
before,  and  photographed  it.  As  it  v/as  in  all  its  details 
exactly  similar  to  Fig.  22  there  is  no  need  to  reproduce  it. 
I  then  proceeded  to  treat  the 

Edible  Chestnut 

in  the   same  way,  and  photographed  the  two  separate 
halves,  shown  in  Figs.  28  and  29,     The  difference  is  very 


28  ELECTRICAL   STRUCTURE  AND 

remarkable.  At  all  stages  of  development  of  the  horse- 
chestnut  the  seed  substance  is  solid,  and  fills  the  whole  of 
the  space  within  the  inner  membrane  b,  as  shown  in 
Fig.  22,  but  in  the  edible  chestnut  it  is  more  suggestive 
of  a  foetus  in  the  womb,  I  have  cut  some  pods  (un- 
fortunately not  now  available  for  reproduction)  in  which 
the  seed  substance  appeared  in  semicircular  shape,  and 
offered  a  weird  resemblance  to  the  foetus  at  a  very  early 
period  of  its  growth.  Apart  from  that,  however,  there  are 
other  essential  points  of  difference.  Both  in  the  horse- 
chestnut  and  the  edible  variety  the  secretion  is  markedly 
acid,  but  whereas  in  the  first  the  seed  substance  holds  very 
little  liquid,  that  of  the  second  is  so  heavily  charged  with 
it  as  to  fill  or  almost  fill  the  cavity  i,  when  the  pod,  and 
with  it  the  seed,  is  divided. 

In  the  case  of  the  horse-chestnut  the  cut  surface  of  the 
seed  soon  discolours  and  becomes  a  brownish-yellow  ;  that 
of  the  edible  chestnut  remains  white  for  a  much  longer 
time,  although  the  conducting  layer  c  dries  up  almost 
immediately.  One  is  a  seed,  pure  and  simple  ;  the  other 
is  both  a  seed  and  a  food. 

As  will  be  seen  in  Figs.  22  and  28,  the  construction 
electrically  is  much  the  same  in  both  seeds,  but  whereas 
in  the  horse-chestnut  the  seed  substance  is  closely  adherent 
to  the  inner  membrane  b  throughout,  only  a  small  portion 
of  the  seed  substance  of  the  edible  chestnut,  in  the  posterior 
part  of  j,  is  in  its  adolescence  adherent  to  it,  and  this 
part,  as  in  the  horse-chestnut,  penetrates  or  protrudes 
through  the  inner  membrane  by  means  of  a  tongue-like 
projection  to  the  limit  of  the  conducting  layer,  c,  which  is 
thicker  than  in  the  horse-chestnut  seed.  It,  however,  does 
not  connect  with  g  (Fig.  25),  but  is  nearer  the  centre  of  the 
seed  (g  being,  in  the  photograph,  rather  high  up  on  the 
left).  This  tongue  is  enveloped  by  an  insulating  membrane, 
by  which  it  is  separated  from  the  layer  c  and  the  outer 


FUNCTION  IN   PLANT  LIFE  29 

membrane  d,  and  may  be  designed  to  facilitate  induction 
between  the  conducting  layer  and  the  seed  substance, 
inasmuch  as  the  latter,  unlike  the  horse-chestnut,  is  not 
adherent  to  the  inner  insulating  membrane  h,  except  at 
this  point.  Two  considerations  at  least  present  them- 
selves. Capacity  in  the  case  of  vegetables  and  fruits  is 
governed  by  the  nature  and  quantity  of  the  conducting 
liquid  as  well  as  bj^  the  specific  inductive  capacity  of  the 
dielectric,  and  the  area  of  the  respective  plates  or  discs  or 
membranes  and  their  distance  from  each  other  ;  and  upon 
capacity  plus  absolute  insulation  the  life  of  the  vegetable 
or  fruit  depends.  In  the  horse-chestnut — assuming  specific 
inductive  capacity  and  absolute  insulation  to  be  the  same 
in  both — we  have  the  plates  of  comparatively  large  area 
and  close  together,  but  with  very  little  moisture.  In  the 
edible  chestnut  one  of  the  conducting  surfaces,  i.e.,  the 
seed  substance,  is  irregularly  shaped,  is  removed  in  youth 
— except  at  the  posterior  part  of  j — from  the  membrane  &, 
but  contains  a  large  quantity  of  moisture ;  is,  in  fact, 
surcharged.  Actual  test  showed  the  tension  of  the  seed 
substance  to  be  higher  than  that  of  the  horse-chestnut,  and 
this  would  be  in  accordance  with  established  laws.*  But 
what  is  the  purpose  underlying  it  ? 

I  may  be  wrong,  but  a  possible  explanation  presents 
itself. 

Let  us  suppose  that  the  horse-chestnut  seed,  not  being 
intended  for  food,  is  destined  only  to  ripen,  to  fall  from  the 
tree  and  pod,  and  to  be  buried  in  the  earth  to  reproduce  its 
species.  That  would  seem  to  be  the  sole  object  of  its 
creation,  and  nothing  but  the  perfection  of  its  insulation 
would  equip  it  with  a  sufficiently  robust  constitution  to 
enable  it  to  survive  prolonged  exposure  under  conditions 
unfavourable  to  germination. 

*  See  chapter  on  Inductive  Capacity. 


so 


ELECTRICAL   STRUCTURE  AND 


The  edible  seed,  on  the  other  hand,  must,  if  it  is  to  be 
useful  as  a  food,  have  keeping  qualities,  be  able  to  preserve 


tLA^aitue  i&rminai 


Otiier  insulation 

Fig.  28. — Section  of  Edible  Chestnut.     [Original  photo.] 

a,  a,  a,  a,  a  =  positively  charged  white,  pithy  substance  ;  b,  inner 
insulating  membrane  ;  c  —  conducting  layer ;  d  =  outer  insul  iting 
membrane  ;  e  —  seed  substance  ;  j  =  beneath  this  is  the  tongue-like 
projection  ;    i  =  cavity  in  which  the  seed  substance  is  ensconced. 

itself  unimpaired  for  a  considerable  period  of  time,  and  in 
this  we  may  find  a  reason  for  the  quantity  of  moisture  with 
which  it  is,  under  considerable  pressure,    charged.     But 


Fig.  29. — Section  of  Edible  Chestnut  :  the  other  half. 

[Original  photo.] 
The  seed  substance  seen  in  the  central  cavity  is  not  attached  in  any 
way  to  it.     Before  division  of  the  pod  it  formed,  of  course,  part  of  the 
seed  substance  shown  in  Fig.  28. 


it  is  also  a  seed,  and  when  it  is  planted  in  the  soil  and  the 
outer    membrane — or    some    portion    of    it — becomes    a 


FUNCTION  IN   PLANT  LIFE  SI 

conductor,  we  have,  although  in  a  slightly  different  form, 
the  same  electrical  arrangement  as  shown  in  Fig.  22  ; 
the  membranous  covering  of  the  tongue  of  the  seed  sub- 
stance providing  the  dielectric  and  the  seed  substance 
itself  the  inner  or  second  conducting  surface. 

It  is  worthy  of  note  that  in  the  edible  chestnut  the 
white,  pithy,  positively  charged  area  is  larger — other 
things  being  equal — than  in  the  horse-chestnut,  and  this 
might  account  for  the  conducting  layer,  c,  of  the  first 
taking,  as  is  the  case,  a  higher  negative  charge  than 
obtains  in  the  second.  It  may  also  explain  the  slightly 
increased  positive  electrification  of  the  seed  substance  of 
the  former. 

As  regards  what  I  have  termed  a  "  repair  outfit,"  both 
the  horse  and  the  edible  chestnut  exude  upon  their  cut 
surfaces  what  bears  the  appearance  of  a  starchy  secretion. 
This  dries,  and  not  only  checks  further  evaporation  of 
moisture  from  the  seed  substance,  but  to  some  extent 
restores  the  lost  insulation.  In  the  potato  the  phenomenon 
is  particularly  noticeable,  and  the  film  is  very  quickly 
formed.  With  the  chestnuts  the  process  is  slower,  but  is 
a  protective  measure  of  the  same  order.  It  would  be 
interesting  to  see  whether  in  this  case  division  of  the  seed 
prevents  germination. 

Another  matter  to  which  I  should  like  to  call  attention 
is  that  when  freshly  cut,  the  seed  substance  of  the  ripe 
horse-chestnut  is  cream-coloured,  or  rather  white,  with  a 
faint  tinge  of  lemon-yellow.  After  exposure  to  light,  and 
as  soon  as  the  starchy  film  develops,  the  cut  surfaces 
become  yellowish-brown,  with  a  deeper  tint  of  yellow 
showing  beneath.  This  is,  no  doubt,  a  matter  of  electro- 
chemistry, and  as  such  somewhat  beyond  my  purview,  but 
the  suggestion  has  occurred  to  me  that  it  may  be  a  measure 
of  protection  against  actinic  rays,  or  changes  conceivably 
introduced  by  them. 


32  ELECTRICAL   STRUCTURE  AND 

The  Acorn. 

A  beautiful  simplicity  characterises  this  seed,  and  one 
might  well  believe  that  from  it  was  borrowed  the  principle 
of  the  modern  incandescent  electric  lamp-holder. 

As  will  be  seen  from  the  example  given  in  Fig.  30,  the 
cups  in  which  the  acorns  are  seated  are  joined  up,  as  it 
were,  in  series,  while  the  negative  terminal  is  in  the  form 
of  a  circle,  a,  at  the  bottom  of  the  cup  ;  the  seed  carrying 
upon  its  posterior  part  a  circular  protuberance,  b,  which 
seats  exactly  upon  the  contact  a. 


^cnfacl  a  __„„.__,.  ,. „  _. .„. 

Fig.  30. — Acorns.  \Original  photo.] 


Electrically  considered,  the  acorn  is  similar  in  con- 
struction to  the  horse-chestnut  seed.  There  are  three 
insulating  membranes,  and  the  secretion  of  the  seed  sub- 
stance is  also  distinctly  acid.  It  should  have  a  fairly  long 
life  owing  to  the  excellence  of  its  absolute  insulation,  to  the 
ample  provision  of  moisture,  and  to  the  fact  that  it  can 
take  in  positive  charge  from  the  air  through  the  point  at  the 
apex  of  the  seed. 

In  common  with  other  seeds,  such  as  the  Barcelona 
nut,  etc.,  there  are  sometimes  two  seeds  within  the  shell. 


FUNCTION   IN   PLANT   LIFE  33 

When  that  happens  and  the  acorn  is  cut  in  halves  longi- 
tudinally it  presents  the  followinjT  appearance: — 


Fig.  31. — Double  Acorn  in  Section, 

The  sides  and  lower  surfaces  of  1,  2,  3,  4 — ^the  cut 
surfaces  only  being  exposed— are  sheathed  in  insulating 
membranes,  which  extend  to  and  cover  them  from  the  inner 
part  of  the  contact  a  after  the  acorn  has  ripened. 

Cob -Nuts. 

After  discovering  that  Nature  had,  for  a  reason  not 
yet  understood,  joined  up  acorns  in  series,  one  remembered 
that  other  things  with  which  we  are  familiar  are  connected 
either  in  multiple  arc  or  clusters  in  series.  The  cherry, 
with  three  or  more  stalks  tapped  off  a  main  contact,  is  an 
excellent  example  of  this,  and  I  wish  I  had  sketched  or 
photographed  a  group  of  them  when  they  were  in  season. 
Fortunately,  however,  we  had  not  to  look  far  for  other 
specimens  of  the  Great  Electrician's  craft.  It  was  the 
time  of  year  for  cob-nuts,  and  the  cluster  shown  in  Fig.  32 
served  to  illustrate  one  method  of  connecting  which  appears 
to  be  in  the  above  category.  The  main  lead,  the  stalk, 
it  will  be  noticed,  is  unusually  thick.  It  carries  current  to 
supply  four  nuts,  and  if  we  imagine  them  to  be  incandescent 
lamps  instead  of  nuts  we  know  we  should  have  to  make 
similar  arrangements  for  their  supply. 

Where  it  joins  the  base  of  the  cluster,  as  photographed, 
the  stalk  splits  into  four  branch  leads,  each  of  which 
connects  with  a  cup  not  unlike  that  of  the  acorn,  but  out- 
wardly continuous  with  the  foliage,  into  which  the  nut  fits 

D 


34 


ELECTRICAL   STRUCTURE  AND 


to  make  contact  at  its  base.  This,  however,  is  not  small 
as  in  the  acorn,  but  extends  to  the  whole  of  its  posterior 
part.     The  cup,   however,  as  shown  in  Fig.   33,  is  not 


i —  ^eSaiive  ieadfrvm  eudk 


■^sifi 


J'hjitive 


Fig.  32. — Cluster''of'Cob-Nuts. 


\Ofiginal  />ftoto.] 


continuous  with  the  foliage,  but  is  insulated  from  it  by  a 
fibroid   layer   which    separates   it    electrically   from    the 

negative  terminal  or  lead. 


'yVe^afive  cup 


- —  J^ibroid  insvilafindltzuer 
fo  rvkich  Cea,v&Sizre  L-yft/zc''-  --■  •■'■ 

Fig.  33. — Foliage  and  Cup  op  Cob-Nut  opened  out. 

[Original  photo.] 

A  longitudinal  section  of  the  ripe  nut  reveals  much  of 
interest.  The  secretion  is  only  slightly  acid,  and  insulation 
is  regained  in  this  instance  by  the  rapid  exudation  of  a 
wax -I  ike  secretion  upon  the  cut  surfaces.     In  the  specimen 


FUNCTION  IN  PLANT  LIFE  35 

examined  there  was  clear  evidence  of  the  previous  existence 
of  the  conducting  layer,  c,  and  the  three  membranes  were 
present,  i.e.,  the  outer  shell,  a  fibroid  lining  within  that, 
and  a  third  enclosing  what  I  have  termed  the  seed  sub- 
stance. In  lieu  of  the  tongue-like  protuberance  with 
which  the  chestnuts  are  provided  a  sharp  point  projecting 
inwardly  from  the  base  of  the  nut  seemed  to  have  served 
the  same  purpose,  and  at  the  apex  was  another  point 
evidently  open  at  one  time  to  the  air.  In  regard  to 
colouring  there  was  again  in  the  white  of  the  nut  a  faint 
tinge  of  lemon-yellow.  I  exposed  one  half  to  bright  and 
the  other  to  diffused  light  for  four  hours,  when  that  in 
diffused  light  was  apparently  unchanged,  while  the  other 
had  taken  on  a  tint  of  slightly  deeper  yellow. 

The  Electrodes  and  Electrolysis. 

Where  contacts  of  prolonged  duration  are  made,  as 
in  the  foregoing  tests  for  capacity,  suspicion  naturally 
attaches  to  the  electrodes,  and  it  might  be  thought 
that  the  changes  of  polarity  observed  were  due  to 
polarisation.  In  this  connection  I  would  point  out  two 
things,  i.e.  (1)  the  needles  were  in  some  instances 
cleaned  and  reinserted  without  polarity  being  affected, 
and  that  in  the  orange  test  there  were  merely  signs 
of  electrolysis,  and  (2)  that  supposing  1-5  volts  had  in 
ten  minutes  polarised  the  electrodes  inserted  in  the 
fruit  or  vegetable  to  such  an  extent  that  polarity  was 
reversed  for  twenty  minutes,  it  is  difficult  to  see  how  an 
electromotive  force  of  about  0086  volt  (i.e.,  that  of  the 
vegetable  cell)  could  restore  the  original  polarity  in  another 
twenty  minutes  while  the  electrodes  remained  in  position. 
Moreover,  I  have  by  repeated  experiments,  extending  over 
a  course  of  years,  established  the  fact  that  it  is  impossible 
to  alter  the  polarity  of  a  vegetable  cell  by  subjecting  the 


36  ELECTRICAL   STRUCTURE   AND 

needles  to  electrolytic  action  possibly  set  up  when  they  are 
left  in  such  cells  for  several  days  at  a  time.  Another  thing 
of  which  sight  should  not  be  lost  is  the  initial  test  of 
Turnip  No.  2.  The  first  charge  of  ten  minutes  with  1-5 
volts  was  dissipated  in  less  than  ten  minutes,  but  when  the 
absolute  insulation  of  the  vegetable  was  improved  in  the 
manner  described  in  the  second  and  third  tests  it  did  not 
recover  until  thirty-four  minutes  had  elapsed.  The 
electrolytic  action  and  consequent  polarisation  should  have 
been  the  same  in  both  tests,  and  altogether  I  think  it  must 
be  agreed  that  the  weight  of  evidence  is  in  favour  of 
capacity,  and  not  polarisation  of  electrodes,  as  explaining 
the  phenomena,  although  there  can  be  no  doubt  that  the 
electrodes  were  affected  to  some  extent  by  electrolysis. 

Primary  or  Secondary  Cells  ? 

The  problem  is,  no  doubt,  possible  of  solution,  but  in  so 
far  as  1  am  acquainted  with  the  chemistry  of  the  subject, 
I  have  yet  to  hear  of  a  cell  made  by  man  in  which  there 
occurs  no  disintegration  or  no  change,  and  which  cannot 
be  either  polarised  or  discharged  by  continued  short- 
circuiting. 

Some  vegetables  and  fruits,  it  is  true,  are  more  liable 
to  decay  than  others,  but  decay  interferes  with  their 
electrical  activity  only  by  diffusion,  by  breaking  down  the 
protection  between  the  negative  and  positive  elements, 
and,  possibly,  by  setting  up  local  action.  Once  that 
happens  the  process  of  decay  is  very  rapid. 

Their  life — that  is  to  say,  their  edibility  as  well  as 
electrical  activity — appears  to  depend  largely  if  not  to  be 
in  direct  ratio  to  their  absolute  insulation  resistance.  Of 
all  vegetables  the  onion  has  the  highest  and  best  absolute 
insulation,  while  among  fruits  the  apple,  the  pear,  and  the 
quince,  etc.,  are  in  the  premier  class.  I  have  short- 
circuited  onions  through  0-1  ohm  for  many  days  at  a  time 


FUNCTION  IN  PLANT  LIFE  87 

without  finding  in  them  any  evidence  of  polarisation  or 
discharge,  and  as  the  E.M.F.  of  them  all  is  the  same — 
the  current  only  varying  in  accordance  with  Ohm's  law — 
the  onion  is,  in  my  opinion,  an  ideal  standard  cell  of  low 
electromotive  force  for  delicate  galvanometric  work.  The 
apple  and  pear,  offering  as  they  do  smaller  contacts  and 
more  liability  to  diffusion  at  the  points  of  contact,  are 
not  so  generally  useful,  although,  with  care,  they  are 
reliable. 

In  regard  to  plants,  shrubs,  and  trees,  however,  I  have 
observed  that  during  such  time  as  they  are  "  resting,"  as 
in  the  late  autumn,  winter,  and  early  spring  months,  both 
electromotive  force  and  current  fall  off,  and  this  may  be 
due  to  a  deficiency  in  the  quantity  or  flow  of  the  sap,  or 
both. 

As  regards  the  constancy  of  these  cells  I  am  inclined  to 
think  they  must  draw  a  positive  charge  from  the  air  when- 
ever their  potential  falls  below  that  of  the  air,  in  the  same 
way — as  shown  by  the  capacity  tests — they  give  off  to  the 
air  any  excess  of  current  with  which  they  are  artificially 
charged.  No  other  explanation  of  their  long-sustained 
electrical  activity  occurs  to  me,  and  if  they  are  carefully 
examined  it  will  be  seen  that  the  flower  or  foliage  end  of 
fruits  and  vegetables  is  not  sealed  so  thoroughly  and 
effectively  as  the  stalk  or  root.  If  that  is  so  they  are 
storage  cells  in  a  new  sense.  In  other  words,  they  are 
maintained  in  a  state  of  electrical  activity  by  the  air  only, 
and  it  would  not  be  possible,  by  joining  them  up  in  series, 
to  increase  their  electromotive  force  beyond  that  of  the 
air,  because  if  it  could  be  augmented — and  I  do  not  believe 
it  can — by  such  an  arrangement,  any  excess  of  potential 
above  that  of  the  air  would  be  given  off  instantaneously. 
We  have  seen  that  an  artificial  charge  is  retained  for  some 
little  time,  but  that,  inevitably,  the  vegetable  cell  reverts 
to  its  normal  electromotive  force  and  polarity. 


38  ELECTRICAL   STRUCTURE  AND 

Water  in  its  Relation  to  Plant  Life. 

If,  as  it  would  appear,  a  constant  supply  of  electricity 
from  the  earth  is  necessary  to  the  well-being  of  everything 
that  grows  therein,  the  fact  that  dry  soil  is  a  bad  conductor 
of  electricity  assumes  an  important  aspect.  In  the 
experiment  about  to  be  described  a  quantity  of  earth  was 
dug  from  the  garden,  carefully  sifted  and  weighed,  and 
equal  quantities  were  placed  in  three  porcelain  pans  of 
equal  dimensions.  These  were  labelled  1,  2,  and  3.  Nos. 
1  and  2  were  put  in  a  gas  oven  and  baked,  the  soil  being 
frequently  turned  over,  untU  all  moistm-e  was  expelled. 
No.  1  was  then  protected  from  moisture,  and  after  a 
solution  of  one  per  cent,  of  ferro-sulphate  had  been  mixed 
with  the  soil  in  No.  2  it  was  again  baked  until  it  had  become 
dry  ;  No.  3  was  left  untouched. 

A  galvanometric  test  of  pan  No.  1  gave  no  deiflection 
whatever,  whilst  Nos.  2  and  3  (No.  2  being  dry)  exhibited 
no  difference  in  their  electrical  conductivity  ;  pointing  to 
the  fact  that,  considered  as  an  electrolyte,  ferro-sulphate 
was  an  efficient  substitute  for  water.  The  next  step  was 
to  sow  exactly  the  same  weight  of  mustard  seed  in  each  of 
the  three  pans,  which  were  then  placed  in  a  room  in  a 
diffused  light  with  free  access  to  the  air. 

No.  1. — Baked  dry  earth. 

No.  2. — Baked   dry   earth    containing   ferro-sulphate, 

and 
No.  3. — Moist  earth  as  taken  from  the  garden. 

No.  3  was  watered  in  the  usual  manner — ^that  is  to  say, 
care  was  taken  to  keep  the  soil  thoroughly  moist — ^but  Nos. 
1  and  2  were  given  only  ten  per  cent.,  in  the  form  of  spray, 
of  the  quantity  of  water  accorded  to  No.  3. 

The  outcome  of  the  experiment  was  that  while  the  seed 
in  No.  1  did  not  germinate,  the  growth  in  Nos.  2  and  3 
exhibited  no  apparent  difference. 


FUNCTION  IN   PLANT  LIFE  39 

Had  the  experiment  been  carried  out  in  a  frame,  so  that 
the  soil  could  have  received  its  charge  from  the  negative 
earth  instead  of  from  the  positive  air,  the  results  obtained 
would  not  have  been  so  conclusive,  as  percolation  of 
moisture  from  below  could  not  have  been  guarded  against. 
As  it  was,  one  could  reasonably  infer  that  the  small  per- 
centage of  conductive  mineral  in  the  soil  of  No.  2  acted, 
in  conjunction  with  the  Avater,  as  an  electrolyte,  and  so 
relieved  the  latter  of  part  of  its  duties.  I  say  in  conjunc- 
tion with  the  water,  because  without  moisture  there  can  be 
no  conductive  or  inductive  capacity  in  soil  or  in  plant  life. 

It  would  be  interesting  to  learn  whether  in  countries 
subject  to  drought  comparison  has  been  made,  under 
similar  climatic  conditions,  between  districts  where  the 
soil  is  and  is  not  ferruginous.  In  Egypt  the  sand  generally 
contains  some  mineral  salts,  and  a  minimum  of  irrigation  is, 
more  often  than  not,  generously  responded  to.  The 
question  is  one  of  some  importance,  more  especially  in 
relation  to  the  Indian  famine  problem  :  the  rice  plant 
requiring  an  excessive  amount  of  water  for  its  successful 
cultivation. 

The  Effect  of  Electrical  Stimulation  upon  Growth. 

In  A  Text-book  of  Biology,  by  J.  R.  Ainsworth  Davis, 
B.A.,  it  is  said :  "  Electricity  probably  plays  an  im- 
portant part  in  growth,  as  electric  currents  taking  various 
courses  have  been  demonstrated  in  living  plants.  Currents 
artificially  sent  through  a  root  have  been  found  to  retard  its 
growth. ^^ 

The  sentence  in  italics,  taken  without  qualification,  is 
I  think,  incorrect.  It  depends,  in  my  judgment,  upon  the 
sign  of  current  and  the  electromotive  force  employed. 
A  current  of  positive  sign  applied  to  the  root  of  a  plant 
growing  in  the  earth  might  exert  a  retarding  influence,  and, 
similarly,  one  of  negative  sign  to  the  soil  of  a  pot  plant. 


40  ELECTRICAL   STRUCTURE  AND 

But  given  proper  connections  and  an  electromotive  force 
not  greatly  in  excess  of  that  of  the  earth  or  air,  the  effect 
of  electrical  stinmlus  should  be  beneficial. 

This  opinion  is  not  merely  theoretical,  but  a  result  of 
long-continued  experiment. 

Years  ago  I  boiled  one  potato  and  baked  another  for 
fifteen  minutes  and  allowed  them  to  get  cold.  Precisely 
what  had  taken  place  I  do  not  know,  but  they  gave  no 
reversal  of  sign,  and  except  that,  by  reason  of  the  water  in 
them,  they  still  possessed  capacity  were,  so  to  speak, 
electrically  dead.  They  were  then  each  joined  up  by  steel 
needles  to  a  dry  cell  (zinc  to  unprolific  and  carbon  to 
prolific  eye)  and  left  for  twenty-four  hours,  when  they 
were  disconnected.  Thereafter  they  not  only  gave  perfect 
reversals,  but  began  to  sprout  in  a  quite  remarkable 
manner. 

Another  test  was  with  tomato  plants  in  the  greenhouse. 
Hypothetically  a  plant  grown  in  a  pot  is  grown  under 
unnatural  conditions,  because  it  is  cut  off  from  the  negative 
earth-cm-rent  and  compelled  to  take  its  root-charge  from 
the  positive  air. 

I  therefore  planted  twelve  tomato  plants  of  exactly  the 
same  size  and  description  in  pots  of  equal  size  and  with 
uniform  soil.  Six  of  them  were  treated  in  the  usual  manner, 
but  the  other  six  were  connected  directly  with  the  earth  by 
means  of  stiff  copper  wires  from  the  soil  in  each  pot  to  the 
earth  beneath  the  slats  upon  which  the  pots  rested ;  all 
the  plants  being  given  the  same  amount  of  water. 

In  the  end  the  last-named  six  were  infinitely  more 
robust  and  bore  heavier  crops  than  the  others. 

A  third  experiment  was  with  two  onions,  neither  of 
which  exhibited  any  outward  sign  of  growth.  Each  of 
these  w^as  connected  to  a  dry  cell  (1  volt),  but  with 
reversed  connections  ;  the  object  being  to  ascertain  what 
effect,  if  any,  the  polarity  of  the  stimulus  had  upon  growth. 


FUNCTION   IN  PLANT  LIFE  41 

The  two  vegetables  in  question  are  shown  in  Figs.  20  and 
21.  Steel  darning-needles  were  again  used,  and  by  means 
of  these  the  zinc  of  one  dry  cell  was  connected  with  the 
root  and  the  carbon  with  the  foliage  end  of  A  (Fig.  20), 
while  in  the  case  of  B  (Fig.  21)  the  arrangement  was  carbon 
to  root  and  zinc  to  foliage  end.  Both  were  then  left  in  a 
room  in  a  weak  diffused  light  for  five  days  and  then 
sketched. 

The  drawings  are  explanatory  in  themselves,  but  it  is 
worthy  of  remark  that  A  gave  evidence  of  growth  within 
twenty-four  hours  under  what  may  be  termed  natural 
stimulus,  while,  though  it  cannot  be  positively  asserted 
that  in  B  there  was  a  retarding  influence,  it  appeared  that 
growth  was  not  stimulated.  This,  in  a  measure  at  all 
events,  proves  my  point  that  the  value  of  electrical  stimulus 
is  largely  dependent  upon  sign  of  current,  and  lends  colour 
to  the  suggestion  that  the  employment  of  low  electromotive 
forces  in  agriculture  and  floriculture  is  in  harmony  with 
natural  laws. 


42  ELECTRICAL   STRUCTURE  AND 


Chapter  III 

THE  EMPLOYMENT  OF  ELECTRICITY  IN 
AGRICULTURE 

It  is  now  more  than  a  hundred  and  fifty  years  ago 
that  a  Scotsman  named  Maimbray  attempted  to  stimulate 
growth  by  electrifying  the  soil,  and  since  then  experiments 
on  a  large  scale  have  been  and  are  being  carried  out  at 
Helsingfors,  Brodtorp,  Breslau,  the  Durham  College  of 
Science  at  Newcastle-on-Tyne,  and  elsewhere  ;  the  method 
employed  being  high-tension  electricity,  usually  generated, 
I  believe,  by  a  Wimshurst  machine  or  machines,  and  carried, 
by  a  network  of  bare  wires  strung  upon  insulators  affixed 
to  poles  some  six  feet  or  so  in  height,  and  covering  the  field 
in  which  the  vegetables  are  grown. 

The  results  have  occasionally,  it  may  be  frequently, 
been  satisfactory,  but  I  cannot  help  thinking  that,  as  a 
matter  of  possibility,  they  may  have  been  due  to  the 
formation  of  nitrous  oxides  at  the  sparking  points,  and  that 
better  results  may  be  obtained  by  studying  Nature's 
methods  and  endeavouring  in  a  more  modest  and  in- 
expensive way  to  improve  upon  them. 

I  am  reminded,  in  fact,  of  high-frequency  treatment  of 
the  human  body.  It  does  not  rest  upon  any  definitely 
ascertained  scientific  basis,  and  might  be  relegated  to  the 
scrap-heap  without  injury  to  mankind. 

While  my  observations  upon  this  subject  are  specu- 
lative, in  that  no  experiment  upon  a  sufficient  scale  has  yet 
been  made  with  low-tension  continuous  currents,  we  have 


FUNCTION   IN   PLANT   LIFE  43 

some  evidence  of  their  effect  upon  the  onion  when  the 
negative  pole  is  applied  to  the  root  and  the  positive  pole  to 
the  foliage,  and  it  should  be  worth  while  to  experiment 
with,  say,  five  or  ten  volts  similarly  applied  to  a  field  of 
several  acres. 

Another  point  which  should  not  be  lost  sight  of  is  that 
some  plants  suffer  from  chlorosis,  the  disease  being  due  to 
deficiency  of  iron. 

Now,  while  it  is  true  that  the  atmosphere  is  positive  and 
the  earth  negative,  it  also  seems  that  Nature  seldom  if  ever 
relies  entirely  upon  the  constant  and  unintermittent 
maintenance  of  any  single  condition  upon  which  life 
depends,  and  it  is  quite  possible,  even  probable,  that 
electrical  generation  goes  on  in  the  plant  itself.  Most,  if 
not  all,  plants  contain  iron,  and  all  of  them  inspire  oxygen  ; 
two  elements  which,  in  the  presence  of  a  suitable  alkali — 
and  this  we  know  to  be  contained  in  the  protoplasm — are 
capable  of  generating  electricity.  During  periods  of 
drought  the  root-supply  of  current  may,  conceivably,  be 
cut  off  by  non-conducting  dry  earth,  and  if  that  current  is 
necessary  to  the  plant  it. would  perish  had  it  not  any  other 
source  of  supply  ;  whereas  so  long  as  its  protoplasm 
remained  in  a  fluid  condition  it  would,  with  some  measure 
of  independent  generation,  be  better  fitted  to  endure 
hardship.  Take,  for  example,  the  savoy  cabbage.  The 
outer  green  leaves  contain  a  comparatively  large  quantity 
of  iron  (17  milligrams  per  100  grams  of  substance),  and 
those  leaves — standing  out  from  the  closely-folded  heart 
of  the  plant— would  have  the  largest  oxygen  intake.  It 
would  not  be  necessary  for  that  process  to  extend  through- 
out the  plant,  because  it  could  be  continued  from  the  outer 
leaves  by  conduction  and  induction  if  for  any  time  during 
the  twenty -four  hours  even  the  surface  of  the  soil  was 
moistened,  as  by  dew. 

According  to  Sachs,  chlorosis  in  plants  may  be  cured  by 


44 


ELECTRICAL   STRUCTURE  AND 


mixing  a  small  quantity  of  ferrous  sulphate,  in  solution, 
with  the  soil ;  but  even  where  the  disease  does  not  exist  iron 
should,  in  my  opinion,  be  used  as  an  electrolyte  and  the 
result  noted. 

Note  for  Guidance  in  Testing. 

For  everything  that  grows,  either  in  the  earth  or  in  a 
pot,  it  is  only  necessary  to  have  flexible  wires  of  low 
resistance  and  of  a  sufficient  length  to  span  the  space 
between  the  galvanometer  and  the  plant.  Both  wires 
should  terminate  in  two  darning-needles  of  equal  gauge  and 
length.  One  needle  may  be  inserted  in  the  open  ground 
or  in  the  soil  in  the  pot,  and  the  other  carefully  placed  in 
between  the  lignified  fibres  in  the  venation  of  a  leaf,  i.e.,  in 
the  interspaces,  or  areolae,  which  are  filled  up  with  tran- 
spiratory  assimilating  tissue.  Contact  with  the  venation 
may  introduce  error,  but  if  ordinary  care  is  taken  there 
will  not  be  any  discordant  result.  The  needles  must,  of 
course,  be  kept  scrupulously  clean,  and  should  not  be 
insulated  for  any  portion  of  their  length,  as  such  insulation 


a,  a,  a,  a  are  the  areolae.     The  needle  should  be  inserted  as  shown. 

— whether  by  india-rubber  or  gutta-percha,  etc. — is  liable 
to  cause   confusion.     Plain,  clean  needles,  well-insulated 


FUNCTION   IN   PLANT  LIFE  45 

wires,  and  clean  ends  to  them  will  save  much  trouble.  If 
the  connecting  wires  are  of  sufficiently  low  resistance  it 
does  not  matter  whether  the  object  to  be  tested  is  one  yard 
or  one  hundred  yards  from  the  galvanometer. 

In  order  to  make  my  meaning  quite  clear  I  have  given 
a  sketch  of  a  part  of  a  leaf  of  Anthyllis  Vulneraria.  The 
enclosed  interspaces,  or  some  of  them,  are  those  which 
should  be  connected  up,  while  the  dark  parts  are  those 
which  should  be  avoided. 


Part  II 
STUDIES  IN  ELECTRO-PHYSIOLOGY : 
ANIMAL        AND        VEGETABLE 


Chapter   IV 

REVIEW    OF   ELECTRO  PHYSIOLOGICAL 
RESEARCH 

Put  briefly,  the  history  of  electro-physiological  research  is 
one  of  contradiction,  confusion,  and  uncertainty.  To  this 
day  the  medical  profession  regard  with  a  not  unmerited 
degree  of  suspicion  the  results  and  theories  of  those  very 
able  men  who  have  for  the  last  hundred  and  thirty 
years  or  so  laboured  in  this  field  of  scientific  investigation. 
Had  it  not  been  for  their  failure  to  discover  certain  facts 
of  primary  importance,  facts  which  would  have  made  all 
things  clear  to  them,  electro-physiology  would  long  ago 
have  enlightened  and  led  the  world  of  medicine. 

Later  on  I  will  give -those  facts  the  prominence  they 
deserve,  but  before  doing  so  it  may  be  useful  to  offer  a 
short  recapitulation  of  what  has  been  done. 

From  A  Practical  Treatise  on  the  Medical  and  Surgical 
Uses  of  Electricity,  by  G.  M.  Beard,  M.D.,  and  A.  D.  Rock- 
well, M.D.,  I  quote  the  following  : — 

"  Those  who  aspire  to  mastership  in  electro-thera- 
peutics will  not  be  content  with  the  mere  attempt  to  relieve 
symptoms  ;  they  will  seek  to  study  those  most  complex 
and  subtle  diseases  for  the  treatment  of  which  electricity  is 
indicated  ;  they  will  resort  to  this  force  for  diagnostic  as  well 
as  therapeutic  aid  ;  they  will  strive  to  know  not  only 
how  to  use  it,  but,  what  is  more  difficult,  how  not  to  use  it. 
He  only  can  reap  the  full  and  rich  harvest  of  electro- 
therapeutical  science  and  art  who  sows  beside  all  ivaters  ; 

49  £ 


50        STUDIES  IN  ELECTRO-PHYSIOLOGY: 

he  must  become  more  or  less  proficient  in  nem'ology,  in 
electro-physics,  and  in  electro-physiology.  He  who  has  a 
knowledge  of  the  laws  of  animal  electricity,  and  the  actions 
and  reactions  of  franklinic,  galvanic,  and  faradic  electricity 
on  the  brain,  spinal  cord,  and  sympathetic  ;  on  the  nerves 
of  motion  and  of  common  and  special  sense  ;  on  voluntary 
and  involuntary  muscles  ;  on  the  skin,  and  on  all  the 
various  passages  and  organs  of  the  body  in  health,  and  also 
of  the  electro-conductivity  of  the  body,  will  find  the  paths 
of  electro-diagnosis  and  of  electro-therapeutics  illumined  at 
every  step  by  such  knowledge,  and  will,  in  the  end,  make 
more  correct  interpretations  of  disease  than  he  who  merely 
holds  electrodes  on  patients  without  any  higher  aim  ;  and 
more  than  that,  he  will  be  introduced  into  a  field  of  thought 
and  experiment — a  field  surpassingly  rich  and  fruitful — 
and  lying  in  close  relation  to  all  departments  of  physiology, 
of  pathology,  and  of  biology,  where  he  can  study  science 
for  its  own  sake."  * 

To  go  back  to  history,  it  was  in  1786  that  Galvani 
discovered  that  muscular  contraction  followed  the  contact 
of  the  nerves  and  muscles  of  a  frog  with  a  heterogeneous 
metallic  arc.  He  theorised,  and  his  theory  was  that  in  the 
tissues  of  animals  there  existed  a  special  independent 
electricity,  which  he  called  animal  electricity.  Later 
observers  admitted  the  existence  of  animal  electricity  as 
a  force,  but  explained  it  by  contact  of  dissimilar  substances 
and  by  the  chemical  action  of  the  fluids  of  the  body  on  the 
metals.  This  erroneous  and  untenable  theory  is  upheld  by 
the  average  physiologist  of  to-day. 

Volta's  researches  followed,  and  in  1799  Humboldt 
published  a  work  which  went  to  show  that  Galvani  and 
Volta  were  both  right  and  both  wrong  ;  that  there  was  such 
a  thing  as  animal  electricity  ;  that  Galvani  was  in  error  in 

*  The  italics  are  mine. 


ANIMAL   AND   VEGETABLE  51 

regarding  it  as  the  only  form  of  electricity  that  appeared  in 
his  experiments  ;  and  that  Volta  was  wrong  in  refusing  to 
admit  its  existence. 

In  1803  a  nephew  of  Galvani,  Aldini,  published 
experiments  that  went  to  demonstrate  the  existence  of 
animal  electricity.  The  voltaic  pile,  however,  was  a 
stronger  argument  against  the  existence  of  animal  elec- 
tricity than  any  experiments  coidd  be  in  its  favour,  and  for 
these  reasons  animal  electricity  was  forgotten. 

The  electromotive  force  of  a  voltaic  pile  would  be, 
approximately,  1  volt  per  cell,  while  that  of  the  human 
body  is,  also  approximately,  0-004  volt  in  its  entirety.  It 
is  difficult  to  see  how  Aldini  arrived  at  his  conclusion. 

In  1827  M.  Nobili,  having  constructed  a  very  sensitive 
galvanometer,  claimed  to  have  detected  the  existence  of  an 
electric  current  in  the  frog  ;  a  few  years  subsequently 
Matteucci  had  turned  his  attention  to  this  subject,  but  it 
was  reserved  for  Du  Bois-Reymond  to  investigate  most 
clearly  and  most  fully,  if  not  most  conclusively,  the  electric 
properties  of  the  nerves  and  muscles. 

By  these  two  observers  (Matteucci  and  Du  Bois-Rey- 
mond) it  was  believed  to  have  been  shown — 

1st. — That  currents  in  every  respect  like  the  frog- 
current  of  Nobili  were  not  peculiar  to  the  frog,  but  were 
inherent  in  all  animals,  warm  and  cold-blooded — in  toads, 
salamanders,  fresh-water  crabs,  adders,  lizards,  glow- 
worms, and  tortoises,  as  well  as  rabbits,  guinea-pigs,  mice, 
pigeons,  and  sparrows. 

2nd. — That  currents  are  found  in  nerves  as  well  as 
muscles,  and  that  both  are  subject  to  the  same  laws. 

3rd. — That  this  muscular  current  may  be  upward  or 
downward,  and  that  the  current  of  the  whole  limb  is  the 
resultant  of  the  partial  currents  of  each  muscle. 

4th. — That  electricity  is  found  not  only  in  the  muscles 
and    nerves,    but    also    in    the    brain,    spinal    cord,    and 


52        STUDIES  IN   ELECTRO-PHYSIOLOGY: 

sympathetic ;  in  motor,  sensory,  and  mixed  nerves ;  in  a 
minute  section,  as  well  as  in  a  large  mass,  of  nervous  sub- 
stances ;  in  a  small  fibril  as  well  as  in  a  large  muscle  ;  in 
the  skin,  spleen,  testicles,  kidneys,  liver,  lungs,  and 
tendons  ;   but  not  in  fasciae,  sheaths  of  nerves,  and  sinews. 

It  is  over  one  hundred  years  since  Du  Bois-Reymond 
taught  lis  this,  and  we  have  learned  nothing  from  it. 

The  next  prominent  exponent  of  electro-physiology 
was  Dr.  C.  B.  Radcliffe,  who  sought  to  prove  that  the 
sheaths  of  fibres  of  nerve  and  muscle  during  rest  are 
charged  with  electricity  like  Leyden  jars.  He  postulated 
the  theory  that  the  sheaths  of  the  fibres  were  dielectric, 
but  did  not  attempt  to  differentiate  the  "  open  "  from  the 
"  closed  "  circuits  of  the  nervous  system. 

He  said :  "  When  a  nerve  or  muscle  passes  from 
action  to  rest  it  resumes  its  condition  of  charge."  But 
"  elongation,  therefore,  is  the  result  of  charge,  and  con- 
traction of  discharge." 

This  view  is,  of  course,  quite  fallacious.  The  reverse 
obtains.  When  an  impulse  is  conveyed  to  certain  groups 
of  sarcomeres  they  contract ;  when  discharge  takes  place 
they  elongate,  and  are  again  in  readiness  for  charge. 

Then  we  had  Professor  John  Trowbridge,  of  Harvard 
College,  who  cast  grave  doubts  upon  the  interesting  and 
hitherto  accepted  conclusions  of  Du  Bois-Reymond  in 
regard  to  animal  electricity,  and  ascribed  the  whole 
phenomena  as  due  to  the  alleged  fact  that  two  liquids  of 
dissimilar  chemical  character,  separated  by  a  porous 
partition,  gave  rise  to  a  current  of  electricity.  More 
recently  this  somewhat  far-fetched  hypothesis  of  dissimilar 
fluids  has  been  substituted  by  two  dissimilar  metals  ;  i.e., 
electrodes  ;  the  theory  being  that  electrical  action  is  set 
up  between  two  electrically  dissimilar  metals — the  elec- 
trodes— in  the  presence  of  an  exciting  liquid,  such  as  the 
secretion  of  the  sweat-glands. 


ANIMAL  AND   VEGETABLE  58 

This,  I  think,  brings  us  more  or  less  up  to  date,  and 
leaves  the  so-called  science  of  electro-physiology  in  a 
somewhat  hopeless  condition.  No  two  sets  of  observers 
are  in  agreement,  and,  as  a  matter  of  fact,  the  general 
medical  practitioner  has  in  his  heart  about  as  much  respect 
for  electro-physiology  as  he  has  for  manifestations  of  the 
occult. 

All  this  appears  to  be  very  extraordinary  and  difficult 
of  explanation.  How  is  it  that  these  great  men  of  science 
were  not  only  unable  to  agree  but  really  discovered  very 
little  of  service  to  humanity  ?  The  reasons  are  not  far  to 
seek. 

In  the  first  place  they  were  not,  any  of  them,  trained 
Submarine-cable  electricians,  specialists  in  their  work, 
whose  business  it  is  to  acquaint  themselves  with  the 
conditions  under  which  tests  of  such  extreme  delicacy  and 
difficulty  must  be  conducted.  For  this  branch  of  research 
a  specialist  electrician  is  imperatively  called  for. 

The  causes  of  the  confusion,  the  sources  of  error  in  the 
past,  lie,  in  the  main,  in  three  factors  which  have  never  been 
taken  into  consideration,  for  the  reason  that  they  were 
not  discovered.     These  three  factors  are — 

(1)  The  constant  electro-chemical  generation  of  nerve- 

force  in  the  human  body. 

(2)  The  presence  in  that  body  of  great  conductive  and 

inductive  capacity  ;   and 

(3)  The  conductive  and  inductive    capacity  of  every 

liquid  and  every  moist  substance  or  object. 

Let  us  see  how  these  factors  come  into  play  as  sources 
of  error. 

That  the  human  body  generates  static  electricity — by 
muscular  movement — is  well  known,  but  this  charge  can 
be  dissipated  in  a  few  moments  b}-  placing  the  body — 
preferably  by  the  palms  of  the  hands — in  contact  with  an 
earth  plate  of  low  resistance.     That  it  possesses  electro- 


54         STUDIES   IN   ELECTRO-PHYSIOLOGY: 

static  capacity  is  also  known,  because  when  perfectly- 
insulated  the  body  can  be  charged  to  a  high  potential. 
That  it  has  inductive  capacity  also  is  not  so  well  under- 
stood. 

So  far  as  capacitjr  is  concerned,  we  may  liken  the  body 
to  a  collection  of  storage  cells  or  Leyden  jars,  which  are 
liable  to  become  more  or  less  highly  charged,  or  to  have  their 
charge  altered  by  any  direct  or  passing  current  or  exciting 
influence,  or  change  in  exterior  insulation. 

Now,  these  storage  cells  or  Leyden  jars  cannot,  if  they 
depend  for  their  charge  upon  some  outside  source  of 
energy  as  the  exciting  influence,  be  in  a  constant  state  of 
tension,  because  the  outside  current  is  not  always  flowing 
either  to  charge  them  directly  or  by  passing  in  their 
vicinity.  We  must  then  depend  upon  muscular  move- 
ment for  the  charge,  and  if  we  find,  as  we  do  find,  that 
movement  of  any  kind  exercises  only  a  momentary  effect 
upon  the  human  electromotive  force,  and  that,  within 
limits,  such  electromotive  force  continues  to  be  produced 
even  when  the  body  is  absolutely  motionless,  we  must  look 
further  for  the  source  of  energy. 

Causes  which  have  contributed  to  Error. 

We  will  now  take  the  three  factors  I  have  mentioned 
seriatim,  but  before  doing  so  it  would  be  well  to  mention 
that  in  the  majority  of  tests,  upon  which  the  conclusions 
to  be  given  hereafter  are  based,  a  Kelvin  Astatic  reflecting 
galvanometer  of  a  resistance  of  88,000  B.O.T.  ohms  at 
15°  C.  and  perfect  insulation  was  used.  This  instrument 
was  made  for  me  by  Elliott  Bros.,  of  Lewisham,  and  its 
sensibility  was  such  that  a  scale  deflection  of  400  mm. 
from  a  central  zero  could  be  obtained  with  a  current  of 
0*1  micro-ampere.     (See  p.  235.) 

The  electrodes  I  will  describe  later. 


ANIMAL   AND   VEGETABLE  55 

Now,  it  is  quite  clear  that  if  nerve-force,  or.  as  I  prefer 
to  call  it,  neuro-electricity,  is  constantly  generated  in  the 
body,  it  must  be  as  constantly  given  off,  otherwise  the  neuro- 
electrical  pressure  would  become  excessive.  The  absolute 
insulation  of  the  body  is  provided  by  the  skin,  but  the  skin 
is  not  an  insulator  of  very  high  resistance.  Nor  is  its 
resistance  uniform,  any  more  than  the  generation  of 
neuro-electricity  is  uniform  in  all  individuals.  Sign, 
electromotive  force,  and  current  vary  with  the  person  as  much 
as  height,  weight,  and  anthropometric  measurements  vary. 

If  nerve-energy  were  visible  we  should  probably  see 
every  human  being — one  might  say  every  living  thing — 
surrounded  by  an  aura,  or  neuro-electrical  field,  extending 
some  distance  from  the  body  andgradually  fading  into  space. 

We  must,  however,  realise  that  the  rapidity  with  which 
that  neuro-electricity  can  pass  to  earth  must  depend  upon 
the  manner  in  which  the  body  is  protected  or  insulated 
from  the  earth  by  dielectrics  other  than  the  skin.  For 
example,  the  insulation  of  a  carpeted  room  with  the  win- 
dows and  doors  closed  would  be  infinitely  higher  than  if 
the  body  were  exposed. to  the  open  air,  or  in  contact  with 
damp  earth,  or  with  the  hands  touching  some  metallic 
substance  connecting  with  the  earth.  We  may,  in  fact, 
conceive  many  conditions  in  which  the  insulation  of  the 
body  could  be  increased  or  impaired. 

In  considering  "  air  "  as  the  normal  "  earth  "  of  the 
body  it  must  not  be  thought  that  I  am  unsupported  in  the 
view  I  have  taken,  although  physicists  may  not,  so  far, 
have  fully  appreciated  the  conductivity  of  air,  under 
varying  conditions  of  humidity  and  movement,  in  its 
relation  to  that  form  of  energy  called  nerve-force,  or  even 
to  electricity  of  so  low  a  tension  as  4  or  5  millivolts. 

In  his  Physiological  Physics  M-Gregor-Robertson,  who 
will  be  remembered  in  connection  with  the  University  of 
Glasgow,  says  :   "  A  charged  body  in  a  current  of  air  slowly 


56        STUDIES  IN  ELECTRO -PHYSIOLOGY  : 

loses  its  electricity  by  convection.  Particles  of  the  air  com- 
ing in  contact  with  the  body  receive  a  charge,  and  pass  on, 
to  be  succeeded  by  other  pd,rticles,  each  of  which  carries 
off  its  portion,  till  the  whole  charge  is  thus  dissipated." 

Dissipation  by  convection  does  not  fully  explain  the 
phenomenon.  Hot  air,  inferentially,  is  dry  air,  and  dry 
air  is  a  bad  conductor.  All  the  neuro-electricity  given  off 
in  a  room  does  not,  therefore,  form  a  stratum  near  the 
ceiling,  and  a  "  current  of  air  "may  be  variously  construed. 
Anyone  moving  about  in  the  testing-room,  draught  from 
the  door,  window,  or  floor,  or  even  the  breath  of  the  persons 
present  may  create  such  a  current.  In  any  case,  however, 
the  air  is  an"  earth  "  of  high  resistance,  and  the  higher  its 
resistance — dimensions  being  equal — the  quicker  the  at- 
mosphere of  the  testing-room  will  become  charged  with 
neuro-electricity,  because  of  the  increased  difficulty  placed 
in  its  path  to  a  true  "  earth." 

That  being  so,  it  is  evident  that  while  the  generation  of 
neuro-electricity  in  the  body  might  be  deemed  to  be 
constant,  the  dissipation  of  it  cannot  be  so  by  reason  of  the 
varying  conditions  of  exterior  conductivity. 

Another  important  point  to  remember  is  that  the  sign 
of  current  in  individuals  is  not  always  the  same.  The 
palms  of  the  hands,  being  free  from  sebaceous  glands,  are 
the  most  convenient  body  terminals,  but,  until  determined 
by  test,  the  body  resembles  a  galvanic  cell  v/hose  terminals, 
electromotive  force,  and  internal  resistance  are  unknown. 

The  bearing  of  all  this  upon  error  will  soon  become 
apparent.  Let  us  imagine  ourselves  in  a  laboratory,  the 
floor  and  walls  of  which  oppose  considerable  resistance  to 
the  escape  of  electricity,  and  let  there  be  two  people 
reproducing,  say,  the  experiments  of  Professor  Trowbridge. 
We,  however,  will  take  the  precaution  of  testing 
them  for  personal  neuro-electricities,  and,  to  quote  figures 
obtained  in  actual  practice,  say  that  A  gave  a  deflection 


ANIMAL  AND   VEGETABLE  57 

of  2000  mm.  positive  and  B  of  40  mm.  negative  upon  the 
scale  of  the  galvanometer  I  have  mentioned.  After  about 
an  hour,  or  less  (according  to  the  size  of  the  room),  the  air 
of  the  laboratory  would  become  charged  by  reason  of  the 
neuro-electricity  emanating  from  the  persons  of  A  and  B, 
and  as  200  positive  minus  400  negative  --=  200  negative, 
the  air  must  become  negatively  charged,  increasing  in 
tension  or  pressure  with  time  or  varying  with  any  alteration 
in  the  insulation. 

In  this  we  have  one  of  the  sources  of  error.  The  tension 
and  sign  of  the  atmosphere  in  the  testing-room  have 
always  been  unknown  quantities. 

Personal  Capacity 

I  have  not  of  recent  years  taken  any  actual  measure- 
ments, but  the  mean  of  a  former  series  of  tests  gave 
nearly  four  microfarads  as  the  average  capacity  of 
the  body.  Now  if  B  ( =  400  mm.  negative)  touched  A 
( =  200  mm.  positive),  A  would  become  200  mm.  negative 
so  long  as  he  remained  shut  up  with  B,  or,  failing  direct 
contact  between  the  two,  the  air  of  the  room  w^ould 
charge  A  as  certainly  as  water  would  find  its  level.  In- 
ductive capacity  introduces  another  and  equally  per- 
plexing source  of  confusion,  as  a  flash  of  lightning,  a 
powerful  earth-current,  wireless  telegraphy,  or  the  proxi- 
mity of  a  charging  station  or  of  an  electric  railway  or  tube 
would  not  only  affect  the  persons  experimenting,  but  also 
the  subject  of  experiment,  although  a  galvanometer  of 
the  d'Arsonval  type  might  not  be  perceptibly  influenced. 

Capacity  of  Liquids  and  Moist  Substances 

But  that  is  not  all .  Physiologists,  overlooking  conductive 
and  inductive  capacity,  have  invariably  used  what  they  call 
non-polarisable  electrodes,  or  contacts  to  which  the  objects 
under   examination   are   connected,    for   the   purpose   of 


58        STUDIES  IN   ELECTRO-PHYSIOLOGY: 

conveying  the  currents  of  electricity  supposedly  emanating 
from  them  to  the  coils  of  the  recording  instrument.  These 
electrodes  were,  and  are,  moistened  with  some  liquid,  and 
as  all  moist  substances  absorb  electricity  as  a  sponge 
absorbs  water  to  the  limit  of  its  capacity,  it  follows  that 
unless  each  electrode  is  of  exactly  the  same  area  and 
density,  there  will  be  a  controlling  current  from  one  of  the 
two.  It  also  follows  that  if  one  electrode  has  a  thousandth 
part  more  moisture  than  the  other,  an  opposing  electro- 
motive force,  so  to  speak,  may  be  exerted  by  it,  and 
furthermore,  disregarding  minor  details,  those  electro- 
motive forces  would  be  liable  to  variation  from  time  to 
time  by — 

(1)  The  number  of  persons  present  in  the  laboratory  ; 

the  length  of  time  they  remained  there,  and  their 
respective  neuro-electrical  signs  and  electro- 
motive forces. 

(2)  The  nature  of  the  liquid  or  liquids  employed. 

(3)  The  degree  of  absorption. 

(4)  The  area  of  the  electrodes  ;   and 

(5)  The  amount  of  moisture  present  in  the  object  or 

subject  under  examination. 

Let  us  suppose  A  and  B  to  have  been  experimenting 
with  a  piece  of  excised  muscle  in  a  moist  condition  and  to 
have  obtained  certain  data.  Their  results  would  always 
check,  because  the  muscle  would  invariably  have  a  charge 
equal  to  200  mm.  negative. 

Two  other  persons,  C  and  D,  question  the  accuracy  of 
the  published  results  of  A  and  B,  and  proceed  to  verify  or 
disprove  them.  C,  let  us  say,  =  300  mm.  positive  and 
D  150  mm.  negative.  The  resultant  charge  would,  of 
course,  be  representative  of  150  mm.  positive,  the  muscle 
would  be  differently  electrified,  and  the  data  obtained  could 
not  agree  with  the  results  of  A  and  B.  In  the  same  manner 
E  and  F  may  prove  both  A  and  B  and  C  and  D  to  have 


ANIMAL   AND   VEGETABLE  59 

been  hopelessly  incompetent,  and  in  their  turn  be  subjected 
to  similar  criticism  at  the  hands  of  others. 

As  a  great  deal  which  does  not  happen  to  be  true  has 
been  written  about  non-polarisable  electrodes,  it  may  be 
well  at  this  juncture  to  give  an  account  of  a  few  experiments 
which  were  carried  out  with  the  object  of  exploding  some 
cherished  theories. 

I  found  that  when  two  wires  of  equal  gauge  and  length, 
soldered  to  two  steel  needles  of  exactly  the  same  gauge 
and  length,  were  connected  to  the  terminals  of  the  gal- 
vanometer, and  the  needles  were  inserted  in  various  objects 
and  liquids,  certain  deflections  were  observed — deflections 
which  were  not  momentary,  but  more  or  less  constant. 

These  deflections  are  explained  as  being  due  to  galvanic 
action. 

There  are  two  theories,  i.e. — 

(1)  Two    metals — that    is  to  say,    one  electrode  being 

electrically  positive  to  the  other — in  one  solution, 
or 

(2)  One  metal  in  two  solutions. 

It  will,  however,  be  only  necessary  to  consider  the  first 
seriously,  inasmuch  as  there  cannot  be  two  different  fluids 
in  distilled  water,  while  the  most  careful  analysis  has 
failed  to  reveal  the  presence  of  two  widely  differing  solu- 
tions in  the  juices  of  fruits  and  vegetables.  Nor  can  the 
first  hypothesis  be  sustained,  if  only  for  the  reason  that  the 
sign  of  the  deflection  obtained  is  not  altered  by  the  reversal 
of  the  needles  upon  the  terminals  of  the  galvanometer. 

In  the  case  of  liquids  such  as  distilled  water,  and  all 
lifeless  moist  objects,  the  deflections  given  by  them  must 
be  of  the  same  sign,  and  that  sign  is,  and  must  be,  governed 
by  the  sign  of  the  electricity  or  neuro- electricity  with  which 
the  air  of  the  testing-room  is,  for  the  time  being,  charged ; 
that  is  to  say,  when  the  two  wires  and  electrodes  are  of  the 
same  metal  and  of  equal  resistance,  the  deflections  which 


60        STUDIES   IN  ELECTRO-PHYSIOLOGY: 

occur  are  always  ascribable  to  charge  imparted  by  some 
source  or  vehicle  of  energy  to  the  article  under  examination. 

As  I  have  before  remarked,  it  is  owing  to  this  fact,  and 
to  the  further  important  truth  that  all  fluids  and  moist 
objects  possess  conductive  and  inductive  capacity,  that  the 
results  obtained  by  various  investigators  have  so  materially 
conflicted. 

But  when  under  the  same  conditions  we  test  anything 
in  which  there  is  life,  we  have  different  factors  to  deal  with. 
In  the  section  upon  Electrical  Structure  and  Function 
in  Plant  Life  I  have  given  a  summary  of  some  ten  thousand 
tests  of  fruits  and  vegetables  in  which  I  used  steel  darning- 
needles  as  the  electrodes,  but  one  or  two  of  them  may  be 
repeated  here. 

First  theory  :  Take  two  equal  lengths  of  insulated 
flexible  copper  wire  and  solder  to  each  length  a  steel 
darning-needle,  connecting  the  other  ends  to  the  terminals 
of  the  recording  instrument.  Call  the  needles  R  and  L 
respectively. 

Now  select  a  sound  onion  and  insert  the  R  needle  in 
the  root,  and  the  L  needle  in  the  foliage  end.  Upon 
depressing  the  galvanometer  short-circuit  key  a  constant 
negative  deflection  will  be  observed.  Theoretically,  there- 
fore, the  L  needle  is  electrically  positive  to  the  R  needle, 
and  the  juice  of  the  onion  being  the  exciting  liquid  galvanic 
action  is  set  up.  If  that  is  so,  and  if  we  do  not  reverse  the 
connections,  the  polarity  of  the  needles  is  established,  and 
we  must  continue  to  get  a  negative  deflection,  no  matter 
where  we  insert  the  needles.  If,  however,  the  onion  is 
reversed,  so  that  the  R  needle  is  in  the  foliage  end  and  the 
L  needle  in  the  root,  there  will  be  an  equally  constant 
positive  deflection,  showing  that  the  difference  in  polarity 
is  in  the  vegetable,  and  not  in  the  needles. 

Again,  take  two  suitable  electrodes,  say  two  silver  rods 
6  in.  by  |  in.,  provided  with  terminals  ;    attach  them  to 


ANIMAL  AND   VEGETABLE  61 

two  equal  lengths  of  wire  and  connect  as  before.  Hold  the 
R  electrode  in  the  right  and  the  L  electrode  in  the  left  hand, 
being  careful  that  the  pressure  is  equal.  The  sign  of  the 
deflection  is,  we  will  say,  positive.  It  follows,  therefore, 
that  the  R  electrode  is  electrically  positive  to  the  other. 
Leave  the  connections  unaltered,  but  hold  the  R  electrode 
in  the  left  and  the  L  electrode  in  the  right  hand.  If  the 
polarity  is  in  the  electrodes  the  sign  of  current  will  be  the 
same.  But  it  is  not.  The  deflection  will  be  negative, 
because  polarity  is  in  the  hands  and  not  in  the  electrodes. 
In  this  connection  proofs  can  be  multiplied  almost  ad 
infinitum,  but  I  do  not  wish  the  case  to  rest  upon  my 
unsupported  testimony. 

In  an  article  in  the  Lancet  of  January  13,  1917,  Dr. 
C.  Nepean  Longridge,  F.R.C.S.  Eng.,  M.R.C.P.  Lond., 
who  has  been  examining  and  treating  various  cases  on  my 
principles  for  some  two  years,  says — 

"  Experiment  1. — With  the  aid  of  Miss  Flecker,  at  the 
Ladies'  College  Physical  Laboratory,  Cheltenham,  I 
estimated  the  electrical  resistance  of  a  piece  of  oak-tanned 
sole  leather  3  in.  long  by  1  in.  wide.  We  found  that  when 
dry  the  resistance  was  practically  infinity.  When  wet  the 
resistance  is  that  of  the  fluid  the  leather  has  soaked  in. 

"  Experiment  2. — One  pole  of  the  galvanometer  was 
connected  to  an  electrode  which  could  be  held  in  the  hand. 
The  other  pole  was  connected  by  an  insulated  cable  to  a 
copper  plate  imbedded  in  the  earth.  Another  insulated 
cable  was  connected  at  one  end  to  the  metal  pipe  supplying 
water  to  the  house,  and  at  the  other  end  to  a  brass  rod  of 
1  in.  section.  After  earthing  myself  I  held  the  brass  rod 
in  one  hand  and  the  electrode  in  the  other,  and  obtained  a 
rapid  off-scale  deflection,  showing,  firstly,  that  an  electric 
current  was  coming  from  my  body  ;  and  secondly,  that  the 
earth  connexions  were  working  properly,  for  the  current 
passed  out  by  one  hand  through  the  brass  tube  to  the 


62        STUDIES  IN   ELECTRO-PHYSIOLOGY: 

water-pipe,  thence  about  20  ft.  through  the  earth  to  the 
copper  plate,  and  through  the  galvanometer  to  the  other 
hand,  so  completing  the  circuit. 

"  Experiment  3. — The  brass  tube  was  then  laid  on  the 
floor,  which  was  covered  by  a  thick  carpet.  I  held  the 
electrode  by  one  hand  and  put  both  feet  on  the  brass 
tube.  I  wore  ordinary  boots,  which  were  dry.  No  deflec- 
tion was  obtained,  because  the  dry  leather  soles  of  my 
boots  insulated  me  from  the  earth.  I  then  took  my 
boots  off  and  put  my  bare  feet  on  the  tube  and  obtained 
an  off-scale  deflection. 

"  Experiment  4. — Next  day  was  wet,  and  I  walked  about 
half  a  mile,  so  that  the  soles  of  my  boots,  which  were  free 
from  holes  and  metal  nails,  became  wet.  On  holding  the 
electrode  in  one  hand  and  placing  my  feet  on  the  brass  tube 
a  rapid  off-scale  deflection  occurred,  showing  that  current 
was  passing  through  my  boots  to  earth. 

"  Experiment  5. — The  pole  of  the  galvanometer  con- 
nected to  earth  by  the  copper  plate  was  disconnected.  It 
was  reconnected  to  a  hand  electrode  exactly  like  the  one 
previously  used,  so  that  the  galvanometer  was  now  con- 
nected to  the  hand  electrodes  only.  After  the  necessary 
earthing  process,  I  heid  the  electrodes  in  the  hands  and 
obtained  a  deflection  which  remained  steady  at  170  mm. 
I  then  placed  my  feet,  still  in  wet  boots,  on  the  brass  tube 
and  awaited  results.  The  light  on  the  scale  very  slowly 
began  to  recede  towards  zero.  I  repeated  this  experiment 
several  times.  The  light  never  remained  at  zero,  but  if  it 
got  as  far  went  over  to  the  other  side  of  the  scale,  and 
generally  registered  40  to  60  mm.  I  take  this  as  evidence 
that  electricity  was  gradually  leaking  out  of  my  body  to 
earth,  through  my  wet  feet.  One  would  not  expect  the 
light  to  register  zero,  as  there  is  a  continuous  generation  of 
electricity  in  the  body.  In  view  of  these  experiments, 
the  grandmotherly  advice  we  have  so  often  received,  not 


ANIMAL  AND   VEGETABLE  63 

to  stand  about  in  wet  boots,  takes  on  a  new  and  important 
significance  which  ought  to  claim  our  belated  respect. 
They  also,  to  my  mind,  afford  evidence  that  trench  foot  is 
probably  caused  by  long-continued  leakage  of  electricity 
from  the  feet." 

In  regard  to  experiment  2  it  may  be  urged  by  the 
supporters  of  the  difference  in  metals  theory  that  it  does  not 
present  an}^  new  feature,  while  the  fact  of  there  being  no 
deflection  in  experiment  3  can  be  explained  by  the  absence 
of  moisture  at  one  pole,  and  therefore  of  the  improbability 
of  galvanic  action  taking  place.  Experiments  4  and  5, 
however,  are,  to  my  mind,  quite  at  variance  with  that 
theory,  and  appear  to  negative  the  conclusions  of  those 
who  have  been  and  are  responsible  for  it. 

In  my  work  upon  Electro-Pathology  and  Therapeutics 
I  stated  that  the  thumb  of  each  hand  was  of  opposite  sign 
to  the  fingers  of  each  hand  and  carried  a  greater  quantity 
of  current. 

Dr.  E.  W.  Martin,  who  has  had  some  few  years'  ex- 
perience of  my  methods,  has  sent  me  the  results  of  a  series 
of  tests  carried  out  by .  him,  and  gives  his  conclusions  as 
follows : — 

"  It  would  therefore  appear  that — 
"  (a)  There  is  no  electrical  current  generated  by  two 
metals  in  contact,  even  in  the  presence  of  moisture. 
"  {b)  A  current  passes  when  both  hands  are  in  contact 

with  both  electrodes. 
"  (c)  That  different  conducting  substances  act  differ- 
ently in  their  relation  to  the  body  current. 
"  {d)  That  the  current  cannot  be  due  to  the  moist  skin 
and  metal  only,  as  we  find  that  in  a  complete 
circuit  from  skin  and  metal  to  skin  and  metal 
no  current  is  set  up  so  long  as  one  hand  only  is 
used. 
"  {e)  That  the  thumbs  appear  to  be  electrically  as  well 
as  anatomically  in  opposition  to  the  fingers  of  the 


64        STUDIES  IN   ELECTRO-PHYSIOLOGY: 

same  hand,  and  equally  in  opposition  to  each 
other,  and  that  they  appear  to  form  terminals  of 
a  circuit  with  the  fingers  of  the  same  hand,  as 
when  the  thumb  is  brought  into  contact  a  current 
at  once  passes. 

"  (/)  That  the  approach  of  the  thumb  to  the  electrode, 
even  without  contact,  produces  a  slight  deflection 
which  is  probably  not  static,  as  the  deflection 
remains  after  all  movement,  so  far  as  it  can  be 
controlled,  has  ceased." 

The  main  points  touched  upon  by  Dr.  Martin,  i.e. — 

(1)  That  unless    both  hands  are  used   the  contact  of 

skin  and  metal  will  not  exhibit  electrical  action, 
and 

(2)  That     the  thumbs   are   of    different   sign  to   the 

fingers — 
may  be  very  simply  and  conclusively  proved  in  the  follow- 
ing manner : — 

Take  two  electrodes,  of  the  same  size,  of  copper,  silver, 
or  German  silver,  and  connect  them  by  two  wires  of  equal 
gauge  and  length  to  the  terminals  of  the  galvanometer. 
Insert  one  of  these  electrodes  between  the  first  and  second 
and  the  other  between  the  third  and  fourth  fingers  of  the 
left  hand,  and  do  not  allow  them  to  touch.  No  deflection 
will  be  observed  unless  the  hand  is  wet.  In  that  case  there 
may  be  a  slight  leakage  from  the  thumb.  Then  bring  the 
left  thumb  into  contact  with  one  of  the  electrodes  and  a 
deflection  will  at  once  ensue.  Repeat  the  experiment 
with  the  right  hand  and  the  result  will  be  the  same,  only 
that  the  deflection  ultimately  obtained  will  be  of  opposite 
sign. 

This  experiment  as  conducted  by  Dr.  Martin  is  thus 
described  by  him — 

"  (a)  One  electrode  was  placed  between  the  third  and 
fourth  fingers,  the  other  electrode  between  the 
first  and  second  fingers  of  the  left  hand ;  not 
allowed  to  touch  each  other.     Key  closed,  i.e.. 


ANIMAL   AND    VEGETABLE  65 

Circuit  from  skin  and  metal,  through  galva- 
nometer, to  skin  and  metal.     Deflection,  nil. 

"  (b)  Repeated  with  right  hand.     Deflection,  nil. 

"  (c)  Terminals  allowed  to  touch.     Deflection,  nil. 

"  (d)  Same  position  electrodes,  left  hand.  Thumb 
approximated  to  electrodes.  Deflection,  slight. 
Thumb  touching  negative  pole  electrode.  Deflec- 
tion, negative.  Thumb  touching  positive  pole 
electrode.     Deflection,  positive. 

"  (e)  Same  experiment  repeated  with  right  hand  and 
right  thumb  gave  a  reverse  result,  i.e., 

+  pole   =   deflection    negative, 
—  pole   =   deflection  positive." 

In  order  to  reconcile  these  results  with  the  views  ot 
physiologists  we  should  have  to  assume — 

(1)  There  are  no  sweat-glands  in  or  moisture  upon  the 

fingers  of  either  hand,  and 

(2)  That  the  thumbs    only    contain    sweat-glands  or 

exhibit  moisture,  and  that  their  secretion  or  the 
moisture  is  of  so  opposite  a  character,  chemically, 
as  to  instantly  change  the  polarity  of  the  elec- 
trodes touched  by  them. 
No  comparison  is  possible  between  the  currents  set  up 
by  a  galvanic  cell  and  those  emanating  from  the  human 
body.     The  former  is  a  simple  generator  of  electricity  ; 
the  latter   a  complex  system  from  which  electricity   or 
neuro-electricity  is  constantly  being  given  off.     It  is  only 
necessary  to   establish   a   difference   of  potential   at  two 
points  in  one  or  more  bodies  to  obtain  deflections,  due  to 
direct    or    derived    circuits.     Owing    to    the    absence    of 
sebaceous  glands  in  them,  the  palms  of  the  hands  and  soles 
of  the  feet  are,  no  doubt,  the  natural  "  earths  "  of  the  body, 
but  nerve-energy  must  escape,  to  a  greater  or  lesser  extent, 
from  every  square  inch  of  the  skin. 

Again,  examine,  galvanometrically,  by  means  of  the 
hand-to-hand  deflection,  a  number  of  persons  until  three 

F 


66        STUDIES  IN   ELECTRO -PH  YSIOLOGY  : 

are  found  who  yield  a  positive  and  three  a  negative  re- 
action. If  the  observer  himself  is  of  positive  sign  two 
other  positives  only  will  be  required,  and  vice  versa.  Then 
let  the  testing-room  be  vacated  for  several  hours  and  freely 
ventilated. 

As  a  next  step  introduce  each  of  the  persons  selected  to 
the  testing-room,  one  by  one,  "  earth  "  the  subject  for  five 
minutes,  and  take  the  hand-to-hand  deflection  very  care- 
fully, noting  the  sign  and  number  of  millimetres  and 
ushering  the  subject  from  the  room  before  the  next  one  is 
admitted. 

Let  us  assume  that  the  deflections  are  respectively  as 
follows : — 

Observer  =  250  mm.  positive 

First  subject  =  200 

Second     „       ==  225 

Third       ,,       =250     „     negative 

Fourth     „       =  200 

Fifth        „       =  225 

These  figures  might  not  actually  obtain  in  practice, 
but  they  will  serve  to  illustrate  my  meaning  and  are 
sufficiently  near  to  the  truth. 

Having  registered  the  above  data,  let  the  observer  and 
the  five  subjects  assemble  in  the  testing-room  and  remain 
together  for  a  few  hours,  the  length  of  time  being  dependent 
upon  the  size  of  the  room  and  its  insulation  from  the  earth. 
If  it  is  of  moderate  dimensions,  carpeted,  and  with  doors 
and  windows  closed,  two  hours  should  be  sufficient.  Then, 
without  earthing  and  without  anyone  leaving  the  labora- 
tory, take  the  hand-to-hand  deflections  again,  in  the  same 
order. 

Now,  if  the  differences  in  polarity  and  in  the  number  of 
millimetres  exhibited  by  the  subjects  are  due  to  dis- 
similarity of  metals,  acted  upon  by  different  secretions  of 
the   sweat-glands,   the   deflections   should   be   as   before, 


ANIMAL  AND   VEGETABLE  67 

though  there  might  be  variations  of  a  few  millimetres  due 
to  increased  or  decreased  moisture  or  pressure  of  one  or 
other  of  the  hands.  If,  however,  my  contention  be  correct 
that  we  give  off  neuro-electricity  to  the  air  in  accordance 
with  our  respective  sign  and  electromotive  force,  and 
that  the  body  is  liable  to  be  inductively  influenced,  it  is 
obvious  that  a  common  level  would,  in  time,  be  found,  and 
that  the  resultant  hand-to-hand  deflection  of  each  and 
every  one  of  the  persons  present  must  be  in  the  neighbour- 
hood of  zero. 

That  is  what  actually  happens. 

I  read  somewhere,  but  regret  the  source  is  not  given  in 
my  notes,  that  we  may  consider  as  generators  of  energy  a 
liquid  passing  from  a  higher  to  a  lower  level  ;  heat  passing 
from  a  hot  to  a  cold  body  ;  electricity  flowing  from  a  body 
with  a  high  potential  to  one  with  a  low  potential  ;  move- 
ment transmitted  from  a  body  animated  by  velocity  to 
another  with  less  velocity,  etc.  Thus  energy  depends  on 
the  state  of  the  bodies  in  presence.  There  is  only  an 
exchange  between  them  if  they  are  out  of  equilibrium  ; 
that  is  to  say,  if  they  possess  different  tensions.  One  of  the 
bodies  present  then  loses  something  which  it  yields  to  the 
other  until  their  tensions  are  equalised. 

We  are  well  aware  that  when  two  pieces  of  the  same 
metal  are  placed  in  a  solution  in  a  circuit  in  which  a  current 
of  electricity  is  flowing  electrolytic  action  will  be  set  up. 
Polarisation  is  the  inevitable  consequence  of  any  such 
combination.  But  when  we  are  calculating  forces  it 
behoves  us  to  take  into  consideration  the  difference 
between  a  steam-hammer  and  a  tack-hammer ;  to 
discriminate  between  a  hurricane  and  a  zephyr.  In  a 
single  dry  cell  a  force  of  1,500  millivolts  is  evolved  :  the 
human  machine  is  driven  by  5.  Moreover,  the  electrodes 
used  by  me  for  body-testing  are  of  German  silver,  heavily 
coated  with  chemically  pure  silver,  and  as  they  are  all 


68        STUDIES  IN   ELECTRO-PHYSIOLOGY: 

electro-plated  at  the  same  time  in  the  same  vat  and  with 
the  same  metal,  the  possibility  of  any  dissimilarity  is 
reduced  to  a  minimum.  Furthermore,  contact  with  the 
body  is  not  made  for  a  sufficient  time  for  polarisation  to 
occur.  In  addition  to  that  the  conditions  are  not  identical. 
In  a  galvanic  cell  or  battery  there  are  only  two  terminals, 
positive  and  negative.  In  the  human  hands  there  are  four 
terminals — a  positive  and  negative  to  each  hand — and  this - 
would  again  tend  to  check  polarisation,  even  with  inferior 
electrodes. 

With  these  observations  it  may  safely  be  left  to  the 
impartial  reader  to  hold  the  scales  between  physiologist 
and  physicist.  I  have  laboured  the  point  at  length 
because  it  lies  at  the  root  of  the  whole  matter.  This,  as  I 
believe,  untenable  theory  of  two,  alleged,  dissimilar  metals 
in  the  presence  of  moisture  has  not  only  hampered  progress 
during  the  past  century,  but  is  even  now  being  put  forward 
to  bar  our  way  to  enlightenment. 

The  second  theory — that  of  one  metal  in  two  dis- 
similar solutions — is,  I  venture  to  think,  sufficiently 
disposed  of  by  the  electrical  response  of  earth-grown 
and  pot-grown  plants  and  fruits,  and  calls  for  no  further 
remark. 

Suggestion. — In  much  the  same  way  that  the  average 
cable  electrician  has  been  accustomed  to  attribute  certain 
galvanometric  deflections  to  "  leakage,"  some  physiologists 
seek  to  find  in  "  suggestion  "  an  explanation  of  many  of 
the  proofs  of  successful  treatment  which  have  been  brought 
forward.  In  taking  cardiograms  by  means  of  the  string 
galvanometer  psychological  influences  cannot  be  dis- 
regarded, because  the  heart  can  be  psychologically  in- 
fluenced through  the  cardiac  branches  of  the  vagi,  but,  by 
my  method  of  testing,  the  deflections  registered  by  gal- 
vanometers of  the  Kelvin  or  d'Arsonval  type  are  only 
subject  to  variation  by  differences  of  pressure  upon  the 


ANIMAL  AND   VEGETABLE  69 

electrodes,  which  by  bringing  conductors  nearer  to  the 
surface  of  the  skin  lower  the  skin  resistance. 

Hand-to-Hand  Deflection  and  Thumb  Pressure. — ^The 
importance  of  the  hand-to-hand  deflection,  as  being  the 
measure  of  the  electromotive  force  exerted  in  the  body  at 
the  time  of  testing,  is  fully  treated  in  the  chapter  upon 
Ohm's  law  and  electro-diagnosis,  but  it  may  serve  a  useful 
purpose  to  explain  what  happens  when  there  is  inequality 
of  pressure  of  the  two  thumbs.  The  body  is  connected  in 
the  galvanometer  circuit  by  means  of  two  suitable  metallic 
electrodes,  grasped  in  the  hands,  and  a  certain  deflection  is 
obtained.  The  thumbs  carry  a  greater  quantity  of 
current  than  the  fingers,  so  that  if  one  is  pressed  harder 
than  the  other  the  deflection  is  altered,  while  if  one  thumb 
is  relaxed  and  the  other  pressed  down  there  may  even  be 
a  reversal  of  sign,  because  the  direction  of  current  is 
determined  by  the  path  of  least  resistance. 

Even  some  electricians  of  my  acquaintance  find  this 
difficult  to  understand.  They  are  accustomed  to  reason 
in  terms  of  bare  wires,  and  forget  that  the  wires  or  con- 
ductors of  the  thumbs  have  an  outer  coating,  or  absolute 
insulation,  of  5,000  or  niore  ohms  resistance,  in  the  skin. 
Suppose  this  resistance  to  remain  unimpaired  upon  one 
thumb  and  even  partly  removed  from  the  other,  and  the 
path  of  least  resistance  becomes  obvious.  If,  however, 
polarity  was  in  the  electrodes  and  not  in  the  hands,  no 
reversal  of  sign  could  be  brought  about  by  such  difference 
of  pressure. 

A  simple  diagram  will  explain  the  differences  of  thumb 
pressure. 

Let  the  body  be  represented  by  a  source  or  sources  of 
electrical  energy,  the  arms  by  two  coils  of  equal  resistance, 
and  the  thumbs  by  two  variable  resistance-boxes,  a  and  b. 
The  quantity  of  current  arriving  at  points  c  and  d  will  be 
exactly   equal,    because,   finding   two  paths   of  the   same 


70        STUDIES  IN  ELECTRO-PHYSIOLOGY: 

resistance,  the  current  will  divide  at  the  battery  terminal, 
and  if  a  and  b  are  exactly  balanced  (no  matter  what 
their  resistance)   no  current   will  pass  through  the  gal- 


Fig.  1. 


vanometer.  If,  however,  a  was  less  than  h  there  would  be 
a  transfer  of  part  of  the  current  from  d  to  c,  and  vice 
versa. 

Taking  what  should  be,  but  is  not,  the  science  of 
electro-physiology  as  it  is  to-day,  it  is  a  matter  of  infinite 
wonderment  to  me  that  physiologists  have  all  failed  to 
recognise,  from  their  own  works,  that  the  structure  of  the 
body  is  primarily  electrical.  If  it  is  so  one  cannot  be 
surprised,  in  the  absence  of  such  recognition,  that  the 
practice  of  electro -therapeutics  is  empirical.  A  necessary 
preliminary  to  curative  treatment  is  knowledge  of  the 
human  neuro-electrical  system — ^the  generator  or  genera- 
tors of  nerve-force,  the  natural  conductors  and  dielectrics, 
the  condensers  and  storage  cells  and  their  capacity,  and, 
what  is  of  paramount  importance,  the  influence  of  disease 
upon  any  or  all  of  them.  Until  that  knowledge  is  acquired 
treatment  cannot  be  said  to  rest  upon  a  scientific  basis. 
I  do  not,  of  course,  include  the  surgical  uses  of  electricity 


ANIMAL  AND   VEGETABLE  Tl 

of  high  potential,  but  I  do  most  emphatically  refer  to  high 
frequency — except  as  a  species  of  electro-massage — to  local 
and  general  faradisation,  to  central  and  local  galvanisation, 
and  the  rest  of  it.  I  also  venture  the  opinion  that  we  know 
next  to  nothing  of  the  electro-pathology  of  disease,  that 
we  have  no  recognised  method  of  electro-diagnosis  worthy 
of  the  name,  and  that  by  reason  of  the  errors  of  the  past 
and  the  consequent  unreliability  of  the  data  already 
obtained,  we  should  lose  little  or  nothing  if  we  forgot 
everything  we  had  learned,  and  made  a  fresh  start  under 
improved  conditions  of  research. 

Let  us  examine,  in  the  light  of  what  we  claim  to  be  the 
discovery  of  a  fundamental  truth,  structures  of  the  body 
as  illustrated  and  described  in  modern  and  accepted  works 
upon  Histology  and  Physiology,  and  see  what  we  can  learn 
from  them. 

With  the  evolution  of  body  organs  and  structures,  the 
electrician  has  no  concern  and  can  pretend  to  no  knowledge. 
That  is  not  his  department.  He  can  only  examine  them 
in  their  completed  condition,  interpret  them  as  they  appear 
to  him,  and  give  such  explanations  of  their  construction 
and  functions  as  are  consistent  with  established  physical 
laws.  If  his  conclusions  are  based  upon  truth,  and  not 
upon  mere  theory  or  sophistry,  they  should  not,  cannot, 
conflict  with  any  established  law,  but  must  serve  to  make 
clear  that  which  is  at  present  obscm-e. 

As  a  first  step  we  should,  I  think,  consider  the  nature 
of  the  nerve-current.  To  this  day  no  one  knows  whether 
in  a  galvanic  cell  electrical  begets  chemical  action,  or 
whether  the  force  we  call  electricity  is  generated  by 
chemical  decomposition.  There  is  nothing  in  the  form 
and  appearance  of  the  galvanic  cell  to  afford  the  proof  or 
even  to  guide  us  to  definite  opinion.  That  is  not  so  with 
the  human  body  ;  we  are  not  at  that  disadvantage.  To 
the  careful  observer  the  structure  of  the  human  body  must 


72        STUDIES  IN  ELECTRO-PHYSIOLOGY: 

appear  to  be  primarily  electrical  and  to  be  designed  for 
the  performance  of  electrical  functions,  not  necessarily- 
outweighing  in  importance  those  chemical  changes 
which  are  essential  to  life,  but  taking  precedence  of 
them. 


«k 


ANIMAL   AND   VEGETABLE  78 


Chapter   V 
THE   NATURE    OF    THE    NERVE    IMPULSE 

"  It  may  be  supposed  that  some  electrical  function  is  exercised  by 
oxygen  in  the  blood." — Sir  Humphrey  Davy. 

The   controversy    which   arose   years   ago    between   the 

physiological  and  physical  schools  as  to  the  nature  of  the 

nerve  impulse  has,  so  far,  contributed  nothing  decisive 

to  our  knowledge  of  the  subject. 

"  Theories   there   are   in   plenty,    but    none    of  them 

adequate    to    explain    the    phenomenon."     (Halliburton, 

1915.) 

The  facts  which,  we  are  told,  make  a  chemical  theory 

acceptable  are — 

"  (1)  Analogy  with  muscle,  where  the  propagation  of 
the  muscular  impulse  is  undoubtedly  largely  due 
to  the  propagation  of  chemical  disturbance. 
*'.  (2)  Evidence  that  the  nerve  does  undergo  metabolic 
changes,  as  shown  by  the  necessity  for  oxygen, 
and  the  production  of  minute  amounts  of  carbon 
dioxide. 
*'  (3)  Arrhenius  and  Van't  Hoff  showed  that  a  rise  of 
10°  in  temperature  increases  the  velocity  of  a 
chemical  reaction  to  two  or  three  times  its  original 
rate.  .  .  .  Maxwell's  recent  experiments  show 
that  a  rise  of  10°  C.  approximately  doubles  the 
velocity  of  nerve  conduction.  .  .  .  Woolley  ob- 
tained the  same  figure  from  the  influence  of 
temperature  on  the  rate  of  conduction  in  muscle, 
so  probably  the  conduction  process  is  of  a  similar 
nature  in  both  tissues."     (Halliburton,  1915.) 


74        STUDIES  IN   ELECTRO-PHYSIOLOGY: 

All  this  is  in  perfect  harmony  with  the  hypothesis  that 
the  impulse  is  neuro-electrical.  The  effect  of  a  rise  of 
temperature  upon  liquid  or  semi-liquid  conductors  is  to 
decrease  their  resistance,  or,  in  other  words,  to  increase  their 
conductivity.  It  is  purely  to  my  mind  a  question  as  to 
which  action  is  precedent,  the  electrical  or  the  chemical, 
and  I  do  not  think  that  anyone  can,  after  careful  study  of 
the  structure  of  muscular  tissue,  ganglia,  and  nerve,  doubt 
that  it  is  the  electrical. 

The  physical  theories  in  relation  to  this  question 
compare  the  nerve  impulse  to  the  way  in  which  an  electrical 
charge  is  propagated  along  a  wire,  and,  in  refutation,  the 
slow  rate  of  conduction  in  nerve  and  the  phenomenon  of 
inhibition  are  adduced. 

Now,  it  is  incontrovertibly  true  that  nerve-current  will 
flow  along  a  metallic  conductor,  but  it  is  abundantly 
evident  that  instead  of  being  homogeneous,  as  a  wire  is, 
the  conductors  of  the  body  are  complex.  Halliburton 
tells  us  that  a  nervous  impulse  does  not  necessarily  travel 
along  the  same  nerve-fibre  all  the  way,  and  that  there  is  a 
system  of  relays.  He  adds  that  on  the  onward  propagation 
of  a  nerve  impulse  through  a  chain  of  neurons  its  passage 
is  delayed  at  each  synapse,  "  hence  there  is  additional 
'  lost  time  '  at  each  of  these  blocks."  And  there  are  very 
many  of  them. 

Suppose  that,  instead  of  an  electric  circuit  being  com- 
posed of  an  insulated  cable,  it  was  made  up  of  thousands  of 
cables  and  wires  and  many  thousands  of  condensers  of 
varying  capacity.  Would  the  velocity  of  the  current  be 
the  same  ?  It  would  not.  There  would,  inevitably,  be 
some  "  lost  time  "  at  many  of  the  condensers  by  reason 
of  their  not  receiving  instantaneously  their  full  tension 
charge,  and  owing  to  varying  degrees  of  retardation. 

To  postulate  that  the  nerve  impulse  is  not  of  an  elec- 
trical nature  is  to  accuse  Nature  of  introducing  into  the  body 


ANIMAL  AND   VEGETABLE  75 

certain  processes  which  are  useless  to  man  ;  I  refer  to 
insulating  processes.  If  their  existence  is  disputed,  I  can 
only  reply  that  proof  of  their  presence  is  to  be  found  in 
recognised  works  on  Physiology.  Let  me  make  that  clear. 
Assume  that  we  do  not  know  anything  about  the  nature  of 
the  nerve  impulse,  and  consider  only  the  behaviour  of 
nerves  under  electrical  stimulus  or  irritation.  My  authority 
is  Professor  Rosenthal,  who,  in  his  Physiology  of  the 
Muscles  and  Nerves,  writes  as  follows  :  "If  the  main 
stem  of  a  nerve  is  irritated  by  electric  shocks,  all  the 
fibres  are  invariably  simultaneously  irritated.  On  tracing 
the  sciatic  nerve  to  its  point  of  escape  from  the  vertebral 
column,  it  appears  that  it  is  there  composed  of  four  distinct 
branches,  the  so-called  roots  of  the  sciatic  plexus.  These 
rootlets  may  be  separately  irritated,  and  when  this  is  done 
contractions  result,  which  do  not,  however,  affect  the  whole 
leg  but  only  separate  muscles,  and  different  muscles 
according  to  which  of  the  roots  is  irritated.  Now,  as  the 
fibres  contained  in  the  root  afterward  coalesce  in  the  sciatic 
nerve  within  a  membrane,  it  follows  that  the  irritation  yet 
remains  isolated  in  the  separate  fibres  and  is  not  imparted 
to  the  neighbouring  fibres.  This  statement  holds  good  of 
all  peripheric  nerves.  Wherever  it  is  possible  to  irritate 
separate  fibres  the  irritation  is  always  confined  to  these  fibres 
and  is  not  transmitted  to  those  adjacent.^^  * 

Now,  the  sciatic  nerve  is  composed  of  a  number  of 
bundles  of  nerve-fibres  (some  efferent,  some  sensory).  If 
each  one  was  not  separately  insulated  it  would  be  im- 
possible to  irritate  one  fibre  electrically  without  simul- 
taneously irritating  all  the  others.  Not  only  is  this  so,  but 
each  bundle  is  protected  from  inductive  interference  by  a 
lymph  space  directly  under  the  perineurium  and  cor- 
responding to  the  copper  taping  of  telephone  or  telegraph 

*  The  italics  are  mine. 


76        STUDIES   IN   ELECTRO-PHYSIOLOGY: 

conductors.     Of  what  use  is  all  this  if  nerve  impulse  is  not 
of  an  electrical  nature  ? 

Professor  Rosenthal  admits  that  the  nerve  substance 
offers  resistance  to  the  passage  of  the  nerve  impulse.  He 
says  :  "  It  is  probable  that  the  propagation  proceeds  at 
first  at  a  greater  and  afterwards  at  a  less  speed,"  basing 
this  opinion  upon  Munk's  experiments.  "  Its  propagation 
is  gradually  retarded.  .  .  .  From  this  it  may  be  inferred  that 
a  resistance  to  the  transmission  exists  within  the  nerve, 
and  this  gradually  retards  the  rate  of  propagation." 

Reverting  to  the  question  of  peripheric  nerves,  he  goes 
on  to  say  that  transmissions  or  irritation  from  one  fibre 
to  another  occur  within  the  central  organs  of  the  nervous 
system.  "  But  in  these  cases  it  can  be  shown  with  great 
probability  that  the  fibres  not  only  lie  side  by  side,  but 
that  they  are  in  some  way  interconnected  "  (ganglion-cells 
or  synaptic  junctions)  "  by  their  processes.  In  peripheric 
nerve-fibres  the  irritation  always  remains  isolated.  Their 
action  is  like  that  of  electric  wires  enclosed  in  insulating 
sheaths.  One  of  these  nerves  may  indeed  be  compared  to 
a  bundle  of  telegraph  wires,  which  are  protected  from 
direct  contact  with  each  other  by  gutta-percha  or  by  some 
other  substance.  The  comparison,  however,  is  but  super- 
ficial. No  electrically  isolating  membrane  can  really  be 
discovered  in  any  part  of  the  nerve-fibre,  but  all  their  parts 
conduct  electricity.  When,  as  we  shall  find,  electric 
processes  occur  within  the  nerve,  these  standing  in  definite 
relation  to  the  activity  of  the  nerves,  we  must  assume  that 
isolation  as  it  occurs  in  the  nerves  is  not  the  same  as  in 
telegraph  wires.  We  cannot  trace  the  matter  here  further, 
but  must  accept  the  fact  of  isolated  conduction  as  such, 
reserving  its  explanation  for  a  future  occasion." 

Its  explanation  does  not  appear  to  me  to  present  any 
feature  of  difficulty.  The  endoneurium  of  a  nerve-fibre — 
and  I  am  adhering  to  the  sciatic  nerve — may  be  said  to 


ANIMAL    AND    VEGETABLE  77 

correspond  to  the  gutta-percha  covering  of  the  telegraph 
wire,  but  in  the  case  of  the  telegraph  wire  as  in  the  nerve- 
fibre  no  electrically  isolating  membrane  really  exists  ;  all 
their  parts  conduct  electricity,  and  conduction  is  merely  a 
matter  of  degree.  A  substance  which  will  not  conduct  low 
tension  may  be  an  excellent  conductor  of  high-tension 
electricity,  and  there  is  an  enormous  difference  between  the 
human  electromotive  force  of  four  or  five  millivolts  and 
the  voltage  of  an  induction  shock. 

As  regards  electric  processes  occurring  within  a  nerve 
we  have  in  a  nerve  the  process  of  intra-cellular  action, 
which  does  not  take  place  in  a  wire  in  the  same  way  or  to 
anything  like  the  same  extent,  even  if  it  occurs  at  all. 
There  are  many  points  of  similarity  between  nerve- 
circuits  and  telegraph- circuits,  but  the  two  are  not  identical. 

In  regard  to  inhibition  it  is  at  least  conceivable  that  by 
the  action  of  certain  ganglion-cells  an  opposing  E.M.F.  is 
set  up  in  or  communicated  to  a  nerve-fibre  or  fibres  so  as 
to  produce  a  lessening  of  action  or  diminution  of  impulse. 
It  is  known  that  "  an  impulse  will  in  some  cases  travel 
both  ways."  This  would  necessarily  occur  in  a  circuit  in 
which  there  was  inductive  capacity,  and  a  mere  cursory 
examination  of  such  physiological  diagrams  as  show  the 
direction  given  to  nerve  impulses  by  different  combinations 
of  ganglion-cells  in  sensory  and  motor  paths  should 
sufficiently  convince  the  student  that  such  action  does 
occur. 

Macdonald  reduces  the  phenomenon  of  nervous  con- 
duction to  electrolytic  dissociation  and  association  of 
inorganic  ions,  but  I  fail  to  see  how  this  can  be  caused 
by  potassium  salts  in  organic  combination  within  the  axis 
cylinder,  as  suggested  by  him,  though  some  such  action 
may  occur  within  a  cell.  A  more  reasonable  explanation 
is  electrical  action  set  up  between  oxygen  and  some 
element  electro-positive  to  it  in  the  cell  contents. 


78        STUDIES   IN   ELECTRO-PHYSIOLOGY: 

"It  is  interesting  to  state,  if  only  in  outline,  the  kind 
of  theories  which  are  in  the  air  at  present.  We  must 
await  with  patience  to  see  whether  they  or  any  of  them 
contain  a  germ  of  truth,  or  whether,  like  so  many  theories 
in  the  past,  they  will  be  forgotten  in  the  future."  (Halli- 
burton, 1915.) 

That  is  tantamount  to  a  confession  that  the  chemical 
theory  is  not  altogether  satisfying.  Once,  however,  we 
understand  the  law,  our  knowledge  of  the  full  application 
of  it  will  only  involve  some  further  microscopic  and 
galvanometric  research,  with  our  eyes  wide  open,  to  find 
the  something  which  exists  but  which  we  have  not  seen, 
for  the  simple  reason  that  we  have  not  been  taught  to 
look  for  it. 

In  regard  to  the  analogy  with  muscle  it  must,  I  think, 
be  admitted  on  the  face  of  the  evidence  I  shall  bring 
forward  that  the  structure  and  operation  of  voluntary 
muscular  fibre  offers  a  very  strong  proof  that  muscular 
impulse  is  primarily  due  to  the  propagation  of  neuro- 
electrical,  and  not  chemical,  disturbances.  I  cannot,  in 
fact,  find  any  physiological  argument  which  is  not  more 
in  favour  of  electrical  than  of  chemical  action.  Explana- 
tion of  the  latter  is  often  laborious  and  unconvincing, 
whereas  the  former  is  always  and  in  every  detail 
harmonious. 

The  velocity  of  the  nerve  impulse  in  man  is  said  to  be 
about  120  metres  per  second.  Now,  the  apparent  velocity 
of  an  electrical  current  is  diminished  more  or  less  in  pro- 
portion to  the  capacity  of  the  circuit ;  the  higher  the 
capacity  the  lower  the  velocity,  due  to  retardation. 
A  cable  is  a  homogeneous  structure,  in  the  sense  that  in  the 
circuit  of  which  it  forms  a  part  there  are  no,  or  very  few, 
"  synaptic  junctions  "  to  occasion  delay. 

In  the  human  body  the  velocity  of  the  nerve  impulse  is 
not  everywhere  the  same,  nor  could  it  be  so  unless  the 


ANIMAL  AND   VEGETABLE  79 

inductive  capacity  was  uniform  throughout,  and  this, 
obviously,  is  not  the  case. 

Retardation,  or  the  portion  of  the  current  retained  upon 
the  surface  of  the  wire,  is  also  dependent  upon,  among 
other  things,  the  length  and  diameter  of  the  wire  or,  in 
other  words,  upon  its  resistance.  And  here  note  should 
be  taken  of  the  fact  that  the  effect  of  capacity  is  to  produce 
prolongation  at  the  end  as  well  as  retardation  at  the  com- 
mencement of  a  current ;  so  that  a  current  takes  longer  to 
leave  the  line  than  it  did  to  enter  it. 

"  In  nerves,"  I  learn  from  Landois  and  Stirling,  "  the 
resistance  is  two  and  a  half  million  times  greater  than  in 
mercury,  while  in  animal  tissues  it  is  almost  a  million  times 
greater  than  in  metals."  Taking  the  specific  resistance  of 
copper  as  1,  mercury  (at  57°)  is  approximately  50,  so  that 
the  resistance  of  the  nerve,  taken  longitudinally,  would  be 
50,000  times  greater  than  that  of  copper.  For  liquids  the 
resistances  are  enormous  as  compared  with  metals,  and 
they  are  subject  to  chemical  decomposition  or  change  in 
the  process  of  conduction. 

It  is,  of  course,  extremely  difficult,  if  not  impossible,  to 
calculate  accurately  the  resistance  of  a  living  nerve 
relatively  with  that  of  a  copper  wire  unless  we  are  given  the 
exact  sectional  area  of  the  nerve-conductors,  and,  pro- 
bably, not  even  then.  But  for  curiosity's  sake  it  may  be 
well  to  see  how  the  50,000  times  increase  of  resistance 
works  out. 

We  will  take  two  round  piu-e  copper  wires  of  sectional 
areas  of  0-01  and  0-02  in.  respectively,  and  suppose  them 
to  be  two  nerves  of  the  same  diameter. 

The  resistance  of  a  copper  wire  of  0-01  in.  corrected  to 
100°  F.  is  0-3677  ohm  per  metre,  and  if  we,  for  convenience 
of  calculation,  take  the  maximum  length  of  a  nerve  to  be 
2  metres,  we  have  0-3677  x  2  x  50,000  =  36,770  ohms 
as  its  total  resistance,  or  -:-  6-5  =  5,657  ohms  per  ft.  length 


80        STUDIES  IN   ELECTRO-PHYSIOLOGY: 

Similarly  the  wire  of  0-02  in.  section  with  a  resistance 
of  0-0884  ohm  per  metre  would  give  us  8,840  ohms  total 
resistance  and  1,360  ohms  per  ft.  length,  and  while  this 
brings  us  no  nearer  to  the  actual  resistance  of  a  nerve,  it 
approximates  somewhat  to  the  resistance  of  the  hand-to- 
hand  circuit,  in  which,  by  reason  of  the  absence  of  sebaceous 
glands  in  the  palms  of  the  hands,  skin  resistance  is  much 
lower  than  in  most  other  parts  of  the  body. 

This  conclusion  is  arrived  at  in  the  following  manner  : — 

Upon  the  scale  of  a  reflecting  galvanometer  which  has  a 
sensibility  of  4,000  mm.,  at  a  metre  distance  from  the  scale, 
per  micro-ampere,  the  average  hand-to-hand  deflection  of 
a  person  in  normal  health  is  between  300  and  400  mm., 
equivalent  to  a  current  of  from  0-08  to  0-1  micro-ampere. 

The  mean  of  several  thousands  of  tests  has  shown  the 
electromotive  force  of  man  to  range  between  4  and  5 
millivolts,  and,  as  C  =  ^,  we  can,  knowing  C  and  E,  cal- 
culate R  with  some  approach  to  accuracy.  By  this 
method  we  should  find  the  resistance  of  the  hand-to-hand 
circuit  to  be  over  5,000  ohms,  taking  into  considera- 
tion the  difference  of  sensibility  or  response  to  current 
and  voltage.  The  calculation,  however,  is  not  given  with 
the  confidence  that  would  attach  to  a  bridge  test  in 
which  the  natural  current  was  used,  to  the  exclusion  of 
battery  power. 

5,000  ohms  would  be  lower  by  3,840  ohms,  or  590  ohms 
per  ft.  length,  than  the  wire  of  0-02  in.  sectional  area,  but 
in  the  circuit  in  question  there  are  several  conductors,  and 
among  them  the  main  leads  of  the  thumbs. 

The  resistance  of  nerves,  whatever  may  be  their 
expression  in  ohms,  must  vary  in  many  parts  of  the  body, 
and,  irrespective  of  the  surface  area  of  the  conducting 
plates  or  discs  or  rods  of  the  body  condensers,  have  the 
effect  of  altering  capacity  ;  while  further  variations  are 
introduced  by  the  inconstancy  of  the  human  electro-motive 


ANIMAL  AND   VEGETABLE  81 

force  and  differences  in  the  nature  or  chemical  compo- 
sition of  the  insulating  substance. 

Even  when  in  two  condensers  the  conducting  plates 
are  of  equal  surface-area,  are  equidistant,  and  E.M.F.  is 
constant,  it  does  not  follow  that  their  capacity  will  be  the 
same.  Suppose  the  dielectric  of  one  to  be  paraffin  and  of 
the  other  gutta-percha.  The  specific  inductive  capacity  of 
air  being  taken  as  1,  paraffin  is  1-99  and  gutta-percha  4-2. 
It  will,  therefore,  be  seen  that  upon  charging  these  two 
condensers  to  the  same  potential  difference  the  condenser 
with  the  gutta-percha  dielectric  will  receive  a  charge  about 
2'1  times  greater  than  the  condenser  with  the  paraffin. 
Moreover,  capacity  depends  also  upon  the  thickness  of  the 
dielectric,  in  the  inverse  ratio. 

As  regards  a  comparison  of  the  capacity  of  the  human 
body  with  that  of  a  submarine  cable,  the  average  capacity 
of  the  latter  ranges  at  about  0-3  microfarad  per  knot, 
while  I  have  found  the  former,  using  the  same  battery- 
power,  to  be  nearly  4  micros.  Its  absolute  insulation 
resistance  is,  however,  comparatively  low,  and  charge  is  not, 
therefore,  retained. 

I  extract  the  following.from  one  of  my  old  note-books  : — 

"  When  the  body  was  charged  for  fifteen  seconds  with 
fifteen  cells  the  immediate  discharge  (with  30  ohm  shunt) 
was  220  mm.  Again  charged  for  fifteen  seconds  and 
insulated  for  sixty  seconds,  the  discharge  was  36  mm.,  and 
upon  this  being  repeated  many  times  it  became  evident 
that  by  reason  of  the  low  absolute  insulation  resistance  of 
the  body  the  charge  was  given  off  to  air  in  a  short  period 
of  time.  As  a  result  of  this  and  another  series  of  tests  with 
earth  connections,  I  find  that  the  body,  when  insulated, 
does  not  act  as  a  plate  of  a  condenser  as  regards  the  earth, 
but  that  the  body  itself  acts  in  every  respect  as  a  condenser 
of  low  insulation."  But  there  is  this  to  be  said  :  the  quan- 
tity of  the  charge  communicated  to  the  plates  depends  directly 


82         STUDIES   IN   ELECTRO-PHYSIOLOGY: 

upon  the  electromotive  force  of  the  cells  used.*  In  the  tests 
to  which  reference  has  been  made  the  electromotive  force 
was  20  volts.  The  average  electromotive  force  of  man 
may  be  put  at  a  maximum  of  5  millivolts,  so  that  the 
quantity  of  the  charge  with  20,000  millivolts  would  be 
many  times  greater  than  with  5  millivolts,  and  this,  I 
think,  suggests  (1)  that  although  the  insulating  processes 
of  the  body  are  not  adapted  to  withstand  the  strain  of 
high  tension  (and  capacity  is  regarded  as  a  strain  upon  the 
dielectric),  they  are  adequate  for  the  purposes  for  which 
they  were  designed ;  (2)  that  the  body  can  be  inductively 
influenced  by  any  outside  source  of  electrical  energy  of  a 
potential  appreciably  higher  than  5  millivolts;  and  (3) 
that  as  the  quantity  of  current  exhibited  by  a  healthy  man 
may  be  expressed  as  being  less  than  1  micro-ampere,  we 
are  justified  in  assuming  that  the  law  of  retardation  applies 
with  equal  force  to  the  human  organism. 

In  the  elaboration  of  my  theory  of  the  nature  of  the 
nerve  impulse,  i.e.,  that  it  is  neuro-electrical  and  due  to 
the  association  of  iron  as  the  positive  and  oxygen  as  the 
negative  element,  in  the  presence  of  an  exciting  liquid,  I 
was  confronted  by  the  fact  that  I  could  not,  as  an  elec- 
trician, recognise  or  point  to  any  organ  in  the  body  which 
could  be  said  to  be  a  generating  station.  I  am  indebted  for 
what  may  be  the  missing  link  to  a  communication  from 
Dr.  E.  W.  Martin,  from  which  I  shall  presently  take  the 
liberty  to  quote.  Before  doing  so,  however,  it  may  serve 
a  useful  purpose — as  this  work  is  intended  for  the  guidance 
of  those  who  are  not  familiar  with  applied  electricity — to 
offer  a  few  observations  upon  so-called  positive  and  negative 
currents  ;  my  authority  being  the  text-book  of  Telegraphy^ 
by  Preece  and  Sivewright. 

"  A  current  is  always  supposed  to  flow  from  the  point 
of  higher  potential  to  that  of  lower  potential.     The  former 

*  See  also  p.  91  et  seq. 


ANIIVIAL  AND   VEGETABLE  83 

point  is  taken  to  be  positive  to  the  latter  ;  and,  vice  versd, 
the  lower  is  taken  to  be  negative  to  the  higher  point.  The 
terms  positive  and  negative  currents  are  frequently  used, 
but  they  are  misnomers.  There  is  only  one  current 
flowing  and  it  varies  in  direction.  It  is  quite  correct  to 
apply  the  term  positive  or  negative  to  currents  with  respect 
to  a  given  point,  and  by  those  terms  to  imply  direction  only, 
for  while  stationed  at  a  given  place  currents  may  flow /rom 
or  towards  us  ;  but  what  is  a  positive  current  at  one  point 
is  a  negative  current  at  another.  ...  A  current  can  only 
be  constant  when  we  have  two  points  separated  from  each 
other  by  an  invariable  resistance,  and  maintained  at  the 
same  difference  of  potential." 

We  shall  see,  later  on,  that  in  the  human  body  neither 
the  resistance  of  any  given  circuit  nor  the  same  difference 
of  potential  can  be  maintained  owing,  quite  apart  from 
disease,  to  variations  of  external  temperature  and  the 
fluctuating  nature  of  the  human  electromotive  force ; 
and  the  fact  is  emphasised  that  in  the  estimation  of  body 
deflections  we  must  have  a  fixed  point  of  departure,  and 
that  that  point  should  be  upon  the  central  line. 

We  will  now  consider  Dr.  Martin's  letter  upon  "  The 
Source  of  Body  Energy  and  its  Relation  to  the  Nervous 
System." 

He  says  :  "  The  theory  of  neuro-electricity,  gal- 
vanometric  tests,  and  treatment,  founded  upon  the  theory 
propounded  by  Mr.  Baines,  has  proved  of  value  in  the 
treatment  of  certain  conditions  of  disease.  The  argument, 
therefore,  follows  that  the  basis  of  the  theory  is  sound. 
In  detail,  however,  the  original  conception  of  the  brain 
as  a  generator,  and  the  nervous  system  as  a  carrier,  of  a 
constant  current  came  into  collision  with  established 
physiology,  and  endangered  the  hearing  of  a  piece  of 
scientific  work  of  great  value. 

"  I  advance  a  theory  which  may  bean  explanation,  and 


84        STUDIES   IN   ELECTRO-PHYSIOLOGY: 

which,  if  proved  to  be  correct,  will  range  the  physiologist 
and  the  electrical  expert  on  the  same  side,  while  adding  a 
fresh  conception  of  the  body  as  a  whole  in  relation  to  one 
source  of  life  ;  at  the  same  time  enabling  us  to  more  easily 
understand  galvanometric  readings  of  the  body  energy  and 
to  interpret  them  rightly. 

"  As  a  foundation  of  the  theory,  I  propose  to  start  from 
one  fact  which,  when  analysed,  may  lead  to  a  more  correct 
conception  of  our  source  of  energy.  ,  .  . 

"  The  question  raised  is  one  which,  so  far  as  I  can  see, 
must  be  answered  by  those  who  would  explain  '  neuro- 
electricity,'  equally  with  those  who  deny  its  existence. 
Argument — 

"  The  conditions  before  the  birth  of  a  child,  and 
immediately  after  birth,  offer  a  field  of  thought.  What  is 
it  that  enables  the  child  to  support  an  existence  separate 
from  the  mother  ? 

"  Let  us  examine  the  problem,  bearing  in  mind  that 
what  we  require  from  the  electrical  expert's  point  of  view 
is  (1)  a  linking  up  of  the  body  with  a  source  of  energy,  and 
(2)  an  organ  that  will  act  the  part  of  generator. 

"  Before  birth  the  foetus  is  alive,  but  nutrition,  growth, 
development,  are  carried  out  by  the  action  of  the  maternal 
blood-stream.  Circulation  through  the  foetus  is  estab- 
lished, with  one  important  exception  :  there  is  no  circulation 
through  the  lung. 

"  Digestive  organs,  nervous  system,  etc.,  are  present, 
but  are  functionally  in  abeyance  till  the  act  of  birth  has 
taken  place.  What,  then,  is  the  difference  ?  It  is  the 
act  of  breathing  which  determines  the  separate  existence  of 
the  child  from  the  mother. 

"  Before  this  act  has  taken  place  the  lungs  contain 
neither  blood  nor  air.  Their  function  could  not  be  called 
into  play  until  the  need  arose  to  link  up  the  life  with  its 
future  source  of  energy. 


ANIMAL  AND   VEGETABLE  85 

"  The  act  of  birth,  therefore,  brings  with  it  the  power 
to  use  a  mechanism  by  means  of  which  the  oxygen  of  the 
air  can  be  used  by  the  body.  From  that  moment  the  whole 
of  the  latent  mechanism  is  in  working  activity  and  the 
individual  life  is  complete. 

"  Here  we  are  at  one  with  known  facts.  Let  us  now 
examine  the  electrical  problem  in  this  light.  We  have  seen 
that  we  require  (1)  a  source  of  energy,  and  (2)  an  organ  to 
act  as  generator  ;  i.e.,  an  instrument  or  apparatus  which, 
when  supplied  with  material,  will  generate  force. 

"  We  have  found  the  source  in  oxygen,  and  the  organ 
in  the  body  to  use  it  ;  let  us  see  whether  it  is  possible  to 
carry  this  analogy  further. 

"  In  the  lung  the  state  of  things  is — air  vesicle  and 
capillaries,  the  interchange  between  blood  and  air  being 
oxygen  from  the  air  to  the  blood  to  enter  into  combina- 
tion with  the  haemoglobin  (an  iron-containing  substance), 
and  CO2  from  the  venous  capillaries  going  outwards  to 
air. 

"  Now,  any  change  between  air  and  blood  must  take 
place  through  the  wall  of  the  capillaries,  and  the  physio- 
logical fact  of  the  permeability  of  membranes  at  once 
arises.  Professor  Bayliss'  Physiology,  and  I  think,  quoting 
from  memory,  that  the  work  on  this  subject  has  chiefly 
been  done  b}^  Professor  Sherrington,  states  that  the 
absorption  by  colloid  surfaces  depends  on  the  electrical 
sign  of  the  surfaces  and  the  substance  absorbed,  and  is 
more  an  electrical  than  a  chemical  action.  Also  the  experi- 
ments on  permeability  of  membranes  depend  on  electrical 
balance  and  the  attraction  and  repulsion  of  electro-positive 
and  electro-negative  ions,  and  is  again  a  matter  of  electrical 
rather  than  of  chemical  activity ;  although  it  would, 
perhaps,  be  better  to  say  that  chemical  action  follows  the 
electrical  or  ionic  movement. 

"  Having  found   one  possible   source  of   energy,    one 


86        STUDIES   IN   ELECTRO-PHYSIOLOGY: 

generator,  and  the  medium  for  the  conveyance  of  energy,  let 
us  next  look  at  the  distribution. 

"  The  order  of  distribution  seems  to  bear  some  signifi- 
cance— 

"  l5^, — The  heart  muscle.  Remembering  the  structure 
of  heart  muscle,  its  ganglia,  and  the  functioti 
performed  by  the  heart,  the  call  for  and  supply  of 
this  organ  with  energy  is  paramount. 

"  2nd. — Next  in  order  of  supply  and  importance  is  the 
nervous  system. 

"  8rd. — ^The  other  tissues  and  organs  of  the  body. 

"  The  order  from  the  generator  is,  therefore,  the  pump 
for  circulating  the  carrier,  then  the  nervous  system,  whose 
chief  function,  through  the  sympathetic,  is  the  regulation,  by 
vaso-motor  and  vaso-inhibitory  nerve-fibres,  of  the  blood 
supply  to  all  tissues  and  organs  ;  and  if  we  substitute  the 
word  '  energy '  for  '  blood '  we  can  follow  the  thought 
through.  This  control  is  important  in  disease,  as  it  gives 
the  power  to  send  more  blood  to  the  area  attacked,  and  the 
converse  is  equally  important  as  explaining  a  fallacy  in 
galvanometer  testing,  as  I  will  show  later. 

"  The  voluntary  system  (apart  from  sensation)  has 
chiefly  to  do  with  the  movement  or  the  control  of  muscular 
contraction  resulting  in  movement.  Striped  muscle,  i.e., 
the  muscles  under  the  control  of  the  voluntary  system, 
will  to  the  electrician  at  once  suggest  an  electrical  apparatus 
which  can  be  set  in  motion  on  being  connected  up. 

"  If,  therefore,  the  nervous  system,  sharing  the  common 
energy  of  the  body  with  every  other  cell  and  organ,  has  a 
special  function  of  control  to  perform,  it  must  have  some 
form  of  insulation  or  this  energy  would  be  dissipated 
through  moist  tissue,  and  the  control  of  blood  supply  and 
the  movement  of  muscle  would  be  lost.  It  is  probable, 
indeed  I  think  established,  that  the  electrical  balance  of 
each  cell  membrane  throughout  the  body,  and  the  resulting 
life  of  the  cell,  are  under  the  control  of  and  kept  in  balance 


ANIMAL   AND   VEGETABLE  87 

by  the  sympathetic  nervous  system ;  and  that  this  is  so  is 
again  an  argument  in  favour  of  an  insulation,  without 
which  stability  could  not  be  obtained. 

"  There  may  be  fallacies  which  I  am  unable  to  detect, 
but  my  belief  is  that  in  the  normal  state  in  quiescent  nerves 
there  is  an  electrical  equilibrium,  that  current  passes  only 
on  liberation  of  impulse  from  brain  centres — in  the  case 
of  the  sympathetic  from  emotion  at  one  end  and  from 
irritant  at  the  other — and  that,  to  control  this  discharge  of 
energy,  insulation  is  imperative  and  will  be  demonstrated. 
To  experiment  with  a  cut  nerve  opens  the  road  to  many 
flaws  which  are  obvious, 

"  From  Mr.  Baines' point  of  view  it  is  necessary  to  prove 
this  insulation.  That  impulses  pass  along  a  nerve  is 
granted,  but  that  this  impulse  is  in  the  nature  of  an  electrical 
impulse  has  to  be  shown;  but  to  object  because  the  word 
'  current '  is  used  instead  of  '  impulse  '  seems  an  unneces- 
sary obstacle  to  understanding,  for  the  nature  of  a  current 
may  be  interrupted  as  well  as  continuous. 

"  The  whole  arrangement  of  the  nervous  system, 
nodes,  synapses,  medulla,  sheath,  ganglia,  etc.,  points  to  an 
electrical  system  with  -many  makes  and  breaks,  shunts, 
etc.,  and  we  have  shown  before  that  the  fundamental 
energising  of  the  body  is  an  electrical  phenomenon. 

"  Returning  to  the  blood-stream  and  for  the  moment 
leaving  out  the  specialised  organs  and  glands,  we  come  to 
the  question  of  connective,  fibrous,  and  elastic  tissues. 

"  Subcutaneous  and  other  vascular  connective  tissues 
may  be  regarded  as  the  padding  of  the  body.  We  have  a 
multitudinous  cell-life,  vascularity,  and  a  controlling  nerve 
supply.  Here,  then,  we  have  a  storage  of  energy  separate 
from  the  closed  circuit  of  the  nervous  system  ;  closed  in 
relation  to  the  other  tissues  of  the  body.  In  this  tissue,  as 
in  the  specialised  organs,  the  interchange  from  blood  to  cell 
goes  on,  but  in  this  case  we  get  some  diffusion  through 


88        STUDIES   IN   ELECTRO-PHYSIOLOGY: 

moist  tissues  and  only  partial  insulation  by  the  skin.  This 
no  doubt  gives  us  the  average  reading  on  the  galvanometer 
scale  of  ordinary  normal  deflections,  except  in  the  case  of 
the  finger-tips  and  toes,  which  give  constant  readings  and 
are  probably  the  earth  (air)  outlets  of  the  nervous  system, 

"  At  the  finger-tips,  no  matter  how  dry  the  skin  may 
be,  we  are  always  able  to  measure  a  current.  Also  reversal 
of  sign  is  obtained  from  hand  to  hand  and  from  the  thumb 
to  the  fingers  of  the  same  hand. 

"  With  other  portions  of  the  skin  over  the  body  a  com- 
paratively dry  condition  will  lead  to  no  current  being 
obtained,  while  moisture  will  produce  a  current  equal  in 
E.M.F.  at  any  part. 

"  In  testing  the  body  as  apart  from  the  hand-to-hand 
measurement,  Mr.  Baines  uses  a  larger  electrode  to  a  fixed 
point  and  goes  over  the  body  with  one  of  smaller  diameter. 
By  this  means  the  sign,  which  is  unimportant,  remains  the 
same,  and  it  becomes  easier  to  estimate  the  deflections  due 
to  faulty  condition.  It  has  been  claimed  that  these 
currents  are  '  skin  currents  '  and  that  a  metal  electrode 
of  larger  size,  with  moist  skin,  will  set  up  a  current,  and 
that  the  use  of  electrodes  of  similar  size  will  lead  to  different 
readings,  change  of  sign,  etc.  I  have  elsewhere  shown  that 
skin  and  metal  to  skin  and  metal  through  the  galvanometer 
does  not  always  exhibit  current,  so  we  must  look  further 
for  an  explanation. 

"  If  we  note  the  different  thicknesses  of  the  skin,  apart 
from  pressure  areas,  we  find  that  where  the  greatest  depth 
of  connective  tissue  is,  or  where  there  is  greatest  vascularity, 
the  skin  is,  as  a  rule,  thicker  ;  and  that  even  in  specially 
vascular  areas,  like  the  scalp,  there  is  a  special  arrangement 
of  skin  and  connective  tissue,  we  are  able  to  trace  in  it  some 
purpose.  If,  then,  we  remember  the  fact  that  the  develop- 
ing foetus  is  open,  and  that  later  it  is  joined  down  the 
centre  line,  and  that  fibrous  tissue  is  a  non-conductor,  we 


ANIMAL  AND   VEGETABLE  89 

at  once  can  see  that  by  using  electrodes  of  a  similar  size 
we  should  frequently  obtain  change  of  sign,  which  is  avoided 
by  adopting  Baines'  method. 

"  Mr.  Baines  has  pointed  out  that,  in  testing,  a  slow 
excursion,  say  to  200  mm.,  is  met  with  which  may  be 
mistaken  for  a  leakage  from  the  nervous  system.  Anyone 
using  the  galvanometer  will  soon  learn  to  judge  this 
condition ;  quantity  as  evidenced  by  the  rapidity  of 
excursion  being  the  test  of  a  nerve  flaw. 

"  If  the  theory  advanced  of  the  source  and  distribution 
of  energy  is  correct,  this  false  reading  can  be  explained. 
A  local  vaso-motor  disturbance  would  result  in  increased 
blood  supply.  For  this  read  conveyance  of  energy,  and 
at  once  you  have  a  local  increase  of  potential,  and  the  skin 
insulating  for  a  normal  potential  only,  will  allow  of  the 
larger  escape  and  give  an  excursion,  but  without  the 
quantity  of  a  leakage  from  the  insulated  nervous  tracts 
where  the  potential  is  probably  higher. 

"  It  will  be  understandable  that  the  readings  from  this 
cellular  source  of  energy  are  comparatively  unimportant, 
and  that  the  larger  electrode  may  be  used  to  govern  the 
direction  of  the  flow  without  in  any  way  interfering  with 
the  usefulness  of  the  readings. 

"  An  escape  through  a  flaw  in  the  insulation  of  a  nerve 
would  result  in  diffusion,  through  moist  substance,  of  a 
current  of  much  greater  quantity,  and  give  the  rapid  deflec- 
tion of  larger  extent  which  one  has  learned  to  associate 
with  a  genuine  alteration  in  tissue  metabolism." 

Unfortunately,  as  I  have  said  in  another  chapter,  our 
knowledge  of  condenser  action  in  the  body  is  limited  by  the 
absence  of  information  regarding  the  specific  inductive 
capacities  of  natural  dielectrics.  With  special  reference  to 
the  velocity  of  the  nerve  impulse  the  experiments  of  Dr. 
Le  Bon  are  of  importance.  He  came  to  the  conclusion 
that  electricity  is  able  to  propagate  itself  in  insulators  as 


90        STUDIES   IN   ELECTRO -PHYSIOLOGY  : 

well  as  in  conductors,  but  much  more  slowly  in  the  first 
case  than  in  the  second,  the  velocity  varying  from  a  few 
centimetres  to  300,000  kilometres  per  second.  In  the 
enormous  margin  between  the  two  there  is  ample  room  for 
speculation  as  to  the  causes  which  contribute  to  the 
comparative  sluggishness  of  the  human  nerve-current. 

The  same  authority  showed  that  the  particles  emitted 
by  an  electrified  point  were  identical  with  those  which 
came  forth  from  radium  ;  suggesting,  by  inference,  that 
the  force  known  as  electricity  may  be  made  up  of  more 
than  one  form  of  energy. 


ANIMAL  AND   VEGETABLE  91 


Chapter   VI 
INDUCTIVE    CAPACITY 

As  a  good  deal  depends  upon  a  proper  appreciation  of 
the  function  of  a  condenser,  as  that  apparatus  is  used  in 
telegraphy,  it  may  be  well  to  make  it  clear  ;  taking  as  my 
authorities  Sir  Wm.  Preece,  F.R.S.,  and  Sir  James  Sive- 
wright,  joint  authors  of  Telegraphy. 

"  When  a  quantity  of  electricity  flows  through  a  line 
in  the  form  of  current,  the  first  portion  of  the  current  is 
retained  or  accumulated  upon  the  surface  of  the  wire,  in 
the  same  way  that  a  charge  is  retained  or  accumulated  upon 
the  surface  of  a  Ley  den  jar.  The  quantity  accumulated 
depends  (1)  upon  the  length  and  diameter  of  the  wire, 
(2)  upon  its  distance  from  the  earth  and  earth-connected 
bodies,  (3)  upon  the  insulating  medium  surrounding  the 
conductor, 

"  The  effects  of  capacity  are,  first,  that  it  absorbs  all 
the  electricity  of  a  short  momentary  current  and  prevents 
the  appearance  of  any  current  at  the  distant  station,  and, 
second,  that  as  it  absorbs  the  first  portion  of  every  current 
sent,  it  has  the  same  effect  as  if  it  retarded  or  delayed  the 
first  appearance  of  the  current  at  the  distant  end.  Thus 
the  apparent  velocity  of  the  current  is  diminished  more  or 
less  in  proportion  to  the  capacity  of  the  circuit,  velocity 
being  in  the  inverse  ratio  to  the  capacity. 

"  '  Condenser  '  is  a  term  applied  to  an  apparatus 
usually  composed  of  alternate  layers  of  tinfoil  and  paraffined 


92 


STUDIES  IN  ELECTRO-PHYSIOLOGY: 


paper,  so  arranged  as  to  form  a  flat  Leyden  jar  of  large 
surface,  and  constructed  to  give  any  capacity  that  may  be 
required.     It  may  be  shown  thus — 


Fig.  2. 

a,  a^,  a^,  b,  b^,  b^  are  square  pieces  of  tinfoil  separated  by 
sheets  of  thin  paper  steeped  in  melted  paraffin  wax.  The 
series  a,  a\  a^  are  connected  together,  and  so  are  the 
series  b,  b\  b^.  A  and  B  thus  become  connected  with 
what  may  be  regarded  as  the  inside  and  outside  coatings  of 
a  Leyden  jar,  and  by  putting  one  pole  of  a  battery  to  A, 
and  the  other  pole  to  B,  we  can  communicate  a  charge  to 
the  plates  the  quantity  of  which  will  depend  (1)  directly 
upon  the  electromotive  force  of  the  cells  used,  (2)  directly 
upon  the  total  surface  of  each  series  of  conducting  plates 
opposed  to  each  other,  (3)  inversely  as  the  distance  between 
each  pair  of  plates,  and  (4)  upon  the  nature  of  the  in- 
sulating material  used  to  separate  the  conducting  plates." 
Condensers  are  conventionally  represented  by  parallel 
lines,  i.e. — 


^ 


B 


or 


.^ 


Fig.  3. 

Now,  the  electrostatic  capacity  of  a  line  is  unequally 
distributed,  and  its  working  conditions  are  naturally 
affected  by  this  distribution.     A  circuit  may  be  made  up 


ANIMAL   AND   VEGETABLE 


98 


1F- 

Fig.  4. 


of  overground  wires,  underground  wires  and  cables ;  and 
one  of  the  principal  functions  of  a  condenser,  or  of  a  series 
of  condensers,  is  in  telegraphy  to  compensate  for  and 
regulate  this  inequality  of  distribution.  In  the  human 
body,  whose  circuits  are  infinitely  more  com- 
plex than  the  most  complicated  telegraph 
system,  they  are  not  only  designed  for  the 
performance  of  this  function,  but  for  the 
equally  important  one  of  changing  the  sign  of 
current  from  efferent  to  afferent,  or  vice  versa. 

"  A  simple  condenser  is,  as  we  have  seen,  shown  in  Fig.  4. 
If  we  connect  that. to  a  galvanic  cell  (Fig.  5)  the  charge 
communicated  to  plate  A  will  (if  the  plates 
are  of  the  same  area)  induce  a  charge  of 
equal  tension  but  of  opposite  sign  upon 
plate  B. 

"  The  capacity  varies   directly  as  the 
surfaces  of  the  opposing  plates.     If,  now, 
three  condensers  Fi,  Fo,  Fg,  be  joined  up 
Fig.   6,   the    effect   is   clearly   to   connect 
all  the  A  plates  together,  so  that,  practically,  they  become 


Fig.   5. 

as  shown  by 


Fig.  6. 

one  plate  of  large  area,  and  so  also  with  the  B  plates  ; 
hence,  by  such  an  arrangement,  the  total  capacity  (F) 
becomes 

F  =  Fi  +  F2  +  Fg 


and  the  condensers  are  said  to  be  connected  in  parallel. 

"  Again,  the  capacity  varies  inversely  as  the  distance 
between  the  plates.     Assume  the  distances  in  the  following 


94       STUDIES   IN   ELECTRO-PHYSIOLOGY: 
figure  to  be  _,  -L,  1_ ;  then,  if  the  three  condensers  be 

*1       J^2       *3 

joined  as  shown,  the  B  plate  of  Fi  is  practically  brought 


.^7" 


Fig.  7. 


opposite  that  of  F^,  by  the  connection  of  the  A  plates  of 
Fi  and  Fg,  but  at  distance  sr  +  ^,  and  similarly  with 

1  -'^2 

Fg  and  Fg,  so  that  the    distance  between  plate  B  of  Fi 

111 
and  plate  A  of  Fg  is  ^   +  —  -|-  — ;    and  the  capacity  (F) 

is  therefore 

1 


F 


1 


+  j^ 


When  condensers  are  connected  in  series  their  joint 
capacity  is  the  reciprocal  of  the  sum  of  the  reciprocals  of 
their  respective  capacities,  while  in  parallel  the  joint 
resistance  is  equal  to  the  reciprocal  of  the  sum  of  the 
reciprocals  of  their  respective  resistances.  In  voluntary 
muscular  fibre  the  sarcomeres  are,  in  my  belief,  joined  up 
in  groups  in  series  as  well  as  in  parallel,  and  it  may  serve 


{7 


J) 


— ^|,| , 

Fig.  8. 

a  useful  purpose  to  append  a  practical  illustration  or  two 
from  Submarine  Cable  Testing  and  Working,  by  my  name- 
sake, G.  M.  Baines,  of  the  Eastern  Telegraph  Company. 


ANIMAL  AND   VEGETABLE  95 

Let  C  and  D  (Fig.  8)  represent  two  condensers  with 
capacities  of  15  and  5  microfarads  respectively,  and  B 
cells  of  an  electromotive  force  of  3  volts  ;  the  distance 
between  the  plates  of  C  being  equal  to  a  and  between  those 
of  D  equal  to  b. 


Fig.  9. 


In  the  above  figure  the  same  pair  of  condensers  show 
under  the  conditions  which  actually  regulate  the  test  of 
their  joint  capacity ;  the  inner  plates  of  both  having  been 
eliminated. 

C  and  D  are  now,  to  all  intents  and  purposes,  a  single 
condenser  with,  it  is  important  to  observe,  a  distance 
between  its  plates  equal  to  a  +  b.  Without  calculation  it 
will  be  recognised  that  the  joint  capacity  of  the  pair  must 
be  smaller  than  the  capacity  of  either  of  them  if  tested 
alone,  because  of  the  increased  distance  between  the 
plates. 

Upon  closing  the  battery  circuit  the  outer  plates  of  C 
and  D  are  equally  and  oppositely  charged  to  the  potential 
difference  of  the  battery,  viz.,  3  volts.  When  this  potential 
difference  has  become  established,  the  current  from  the 
battery  will  cease  to  flow.  The  neutral  condition  of  the 
inner  plates  of  C  and  D  has,  meanwhile,  been  disturbed  by 


96        STUDIES  IN  ELECTRO-PHYSIOLOGY: 

the  inductive  effect  of  the  battery  charge,  and  quantities 
of  electricity  equal  to  that  charge,  but  of  opposite  sign  to 
each  other,  will  be  collected  upon  the  inner  plates  ;  these, 
however,  and  therefore  their  electrical  condition,  do  not 
in  any  way  influence  the  joint  capacity  of  the  two  con- 
densers, which  in  accordance  with  the  law  must  be 


tV+* 


20 

T3" 


75 
20 


3-75  microfarads  ; 


the  charge  being  3-75  x  3  =  11-25  microcoulombs,  and 
the  potential  differences  of  the  charges  on  C  and  D  0*75 
volt  and  2-25  volts  respectively. 

Similarly  the  charges  on  three  condensers  of  varying 
capacities,  and  connected  in  series,  as  also  their  potential 
differences,  may  be  shown  by  employing  three  glass  vessels 
for  the  purpose ;  the  larger  the  vessel  the  greater  the 
capacity. 

a  6  c 


Fig.  10. 

a  is  ^  and  h  f  the  size  of  c,  and  we  will  call  the  respective 
capacities  2,  4,  and  6  microfarads  and  the  E.M.F.  of  the 
battery  2  volts. 

The  joint  capacity  of  a,  6,  and  c  will  be — 

1  1 


_  48 


44 
48 


4«  =  ia=i.i  micros. 


The  charges  on  the  three  condensers  will  be  exactly  the 


ANIMAL  AND   VEGETABLE  97 

same  in  amount,  but  their  potential  differences  will  vary  in 
proportion  to  the  plate  areas /,/i,  and/2. 

In  a  the  charge  has  only  a  surface  of  2  microfarads  over 
which  to  diffuse  itself ;  consequently,  as  this  surface  is  the 
smallest  of  the  three,  the  potential  difference  of  its  plates 
will  be  the  maximum.     In  h  it  will  be  only  half  as  great  as 

in  a,  while  in  c  it  can  only  be  equal  to  —  or  — . 

The  sum  of  the  potential  differences  should  equal  the 
E.M.F.  of  the  battery,  and  would  work  out  as  follows  : — 

a  —  1-091  volts  (about) 
h  =  0-545  volt 
c  =  0-364     „ 


Total    2-000  volts 

It  will  thus  be  seen  that  to  raise  a  to  the  same  potential 
difference  as  c,  only  one-third  of  the  charge  it  has  accepted 
in  series  would  be  required.  Similarly  the  joint  capacity 
of  any  number  of  condensers  of  equal  capacity  connected 
in  series  is  the  capacity  of  any  one  of  them  divided  by  their 
number. 

It  will  also  be  seen  why,  if  the  sarcomeres  of  voluntary 
muscular  tissue  are  joined  up  in  series,  it  can  only  be  in 
limited  groups  of  them,  otherwise  capacity  and  potential 
difference  would  approach  the  vanishing  point  before  the 
initial  impulse  had  travelled  very  far.  That  connection  is 
made  in  this  manner,  i.e.,  in  series -parallel,  will  be  apparent 
when  study  is  made  of  the  terminations  of  nerves  in 
muscle  (p.  150). 

We  have  now  learned  some  very  important  facts,  viz. — 

(1)  That  capacity  varies  directly  as  the  surfaces  of 
the  opposing  plates,  (2)  that  the  velocity  of  the  current  is 
in  the  inverse  ratio  to  the  capacity,  and  (3)  that  capacity 
varies  inversely  as  the  distance  between  the  plates.  That 
being  so,  it  follows  :  (1 )  the  larger  the  plate-area  the  greater 

H 


98        STUDIES   IN   ELECTRO-PHYSIOLOGY: 

the  capacity,  (2)  the  greater  the  capacity  the  lower  the 
velocity  of  the  current,  and  (3)  the  closer  the  conducting 
plates  are  together  the  greater  the  capacity. 

In  the  human  body  none  of  the  conducting  plates, 
discs,  or  points  are  of  large  area,  but  while  no  considerable 
variation  of  capacity  is  possible  by  this  means,  Nature  can, 
and  apparently  does,  overcome  the  difficulty  by  approach- 
ing the  conductors  closely  to  each  other,  as  in  striated 
muscular  fibre,  and  by  connecting  them  sometimes  in 
parallel  (as  in  Fig.  6).  In  other  parts  of  the  body  structure 
— in  various  arborisations,  for  instance — there  must  be 
differences  of  capacity  and  resistance,  and  therefore 
velocity  of  current  or  nerve-impulse  cannot  be  uniform 
throughout  the  whole  of  the  nervous  system. 

This  is  an  opinion  arrived  at  after  experiment  and 
careful  thought,  and  I  am  encouraged  to  find  myself 
supported  in  the  view  by  several  authorities.  Halliburton 
says  :  "  The  rate  of  stimulation  makes  no  difference ; 
however  slow  or  fast  the  stimuli  occur,  the  nerve-cells  of 
the  central  nervous  system  give  out  impulses  at  their 
normal  rate. 

"  The  same  is  seen  in  a  reflex  action.  If  a  tracing  is 
taken  from  the  gastrocnemius  of  a  pithed  frog,  the  muscle 
being  left  in  connection  with  the  rest  of  the  body,  its 
tendon  only  being  severed  and  tied  to  a  lever,  and  if  the 
sciatic  nerve  of  the  other  leg  is  cut  through,  and  the  end 
attached  to  the  spinal  cord  is  stimulated,  an  impulse  passes 
up  to  the  cells  of  the  cord,  and  is  then  reflected  down  to 
the  gastrocnemius  under  observation.  The  impulse  has 
thus  to  traverse  nerve-cells  ;  the  rate  of  stimulation  then 
makes  no  difference  ;  the  reflex  contraction  occurs  at  the 
same  rate,  10  or  12  per  second  .  .  .  recent  experiments  by 
Piper  ...  he  found  that  each  wave  of  the  curve  obtained 
by  the  graphic  method  is  really  itself  due  to  fusion  of 
contractions  occurring  at  a  more  rapid  rate.     The  method 


ANIMAL  AND   VEGETABLE  99 

he  employed  was  to  count  the  number  of  electrical  varia- 
tions which  accompany  a  voluntary  contraction,  on  the 
assumption  that  each  fundamental  unit  of  the  contraction 
has  an  electrical  change  as  its  concomitant.  .  .  .  The 
number  of  electrical  variations  is  found  to  be  a  fixed  one 
for  each  muscle,  but  to  vary  in  different  muscles.  Various 
spinal  and  cranial  motor  centres  have  thus  different 
rhythms,  and  of  those  hitherto  studied  the  cells  of  the 
motor  fibres  of  the  fifth  cranial  nerve  have  the  highest 
rate  of  discharge,  86  to  100  per  second.  In  muscles 
supplied  by  spinal  nerves  the  rate  is  lower,  40  to  60." 

Many  other  proofs  could  no  doubt  be  cited,  but  we 
have  an  example  of,  as  I  think,  variation  of  capacity  in 
Purkinje^s fibres  in  the  auriculo-venticular-bundle  of  cardiac 
muscle.  These  are  large,  quadrangular  cells  with  granular 
protoplasm,  and  striated,  it  is  said,  only  on  the  margins. 
The  slow  rate  of  propagation  of  the  wave  suggests  greater 
capacity  than  in  ordinary  striated  muscle,  and  therefore 
either  (1)  the  plates  are  closer  together,  (2)  they  are  larger, 
or,  (3),  what  is  more  probable  and  indeed  indicated  by 
physiological  diagrams,  they  are  connected  in  parallel.  If 
this  is  so  the  argument  should  apply  with  even  greater 
force  to  plain  muscle,  but,  unfortunately,  the  structure  of 
the  latter  is  not  sufficiently  defined  to  enable  a  definite 
opinion  to  be  given. 

In  cardiac  muscle  the  movement  is  rhythmical,  and  it 
differs  from  that  of  voluntary  and  plain  muscle  in  that, 
subject  to  regular  periods  of  rest,  it  is  constant,  whereas 
in  the  others  it  is  intermittent.  We  can  readily  under- 
stand this  when  we  remember  that  discharge  or  neutralisa- 
tion does  not  take  place  instantaneously  unless  there  is 
actual  contact.  Regular  periods  of  time  or  rest  would  be 
necessary  in  any  such  circuit  if  it  was  required  to  work 
continuously  and  automatically.  The  retardative  action 
is  equally  pronounced  in  the  discharge  as  in  the  charge,  and 


100      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

both  velocity  of  impulse  and  periodicity  are  dependent 
upon  the  two  factors  of  resistance  and  capacity. 

It  is  a  pity  that  we  have  no  data  as  to  the  specific 
inductive  capacities  of  the  natural  dielectrics  of  the  body, 
such  as  cholesterol,  neuro -keratin,  lecithin,  kephalin,  the 
medullary  sheath,  etc.,  as  a  basis  for  calculation.  As 
against  the  1  of  air,  sulphur  is  1-93,  but  as  other  dielectric 
substances  range  between  1-77  and  10-1,  it  is  evident  that 
further  research  is  called  for  to  determine  this  important 
point. 

Apart  from,  but  in  addition  to,  specific  inductive 
capacities,  I  should  much  like  to  have  the  following 
information  : — 

In  a  selected  piece  of  striated  muscle — 

(1)  The  surface  area  of  the  clear  spaces, 

(2)  The  thickness  of  Krause's  membrane, 

(3)  The  average  number  of  sarcomeres  connected  by 

the  end-plates  of  motor-nerve  fibres,  and 

(4)  Whether  such  end-plates  do  or  do  not  connect  the 

clear  spaces  thus — 


endpialei 


Fig.  11. 

That  would  be  something  to  go  on  with. 

I  learn  from  The  Human  Species,  by  Ludwig  Hopf, 
that  an  average  size  piece  of  striated  muscular  fibre  measures 
20*4  mm.  in  length  by  0-06  mm.  diameter.  If  we  had  the 
thickness  and  specific  inductive  capacity  of  Krause's 
membranes  we  could,  at  least  approximately,  calculate  the 
capacity  of  each  sarcomere. 


ANIMAL  AND   VEGETABLE  101 

In  plain  muscle  the  figures  given  are  0-045  to  0-225  mm. 
long  by  0-004  to  0007  mm.  wide.  These  are  given  by 
Hopf.  Halliburton  states  that  the  fibres  of  voluntary 
muscle  average  about  1  in.  in  length  and  sho  (0-05  mm.) 
in  diameter. 

To  Test' THE  Body  for  Capacity. 

There  are  several  ways  of  doing  this,  but  as  extreme 
accuracy  is  not  required,  the  most  convenient  method  is  by 
direct  discharge.  For  this  a  "  universal  "  shunt  and  a 
standard  condenser  of  ^  to  1  micro  are  required,  and  the 
subject  should  stand  upon  an  ebonite  slab  to  obtain  good 
insulation. 

Using  fairly  high  power  (say  20  volts)  at  first,  and 
afterwards  not  more  than  0-5  volt,  take  two  sets  of  observa- 
tions in  the  following  manner.  Charge  the  standard 
condenser  Fi  by  the  battery  for  a  given  number  of  seconds 
and  discharge  it  through  a  shunted  galvanometer.  Note 
the  immediate  deflection  and  call  it  d^.  Next,  charge  the 
condenser  to  be  measured  (the  body),  F2,  by  the  same 
battery  ;  discharge  it  through  the  galvanometer  and  again 
note  the  immediate  deflection,  d^.     Then— 

Fi:F2::di:d3,  orFa  =  Fi^' 

Fi  . 
If  —  is  made  a  submultiple  of  10,  dg  gives  the  capacity  at 

once. 

The  multiplying  power  of  the  shunt  or  shunts  used  is 
found  by  the  formula — 

G  +* 


G  being  the  resistance  of  the  galvanometer  in  ohms,  and 
s  the  resistance  of  the  shunt. 


102       STUDIES  IN  ELECTRO -PHYSIOLOGY  : 

The  actual  connections  in  my  original  tests  were  : — 

G 


Body 


N 


-fO 


/5  cells 


InJulated 


!t 


Dischar^eKei/ 


Fig.  12. 

di  was  taken  with  a  standard  condenser  of  1  microfarad 

capacity,  a  galvanometer  resistance  of  7,000,  and  a  shunt 

of  80  ohms.     The  immediate  discharge,  or  d^,  was  204  mm., 

G  4-  s 
or,  multiplied  by =  18,033-6  mm.  ;   while  d^,  with 

a  30-ohm  shunt,  was  290  mm.,  or  67,947  mm.  in  full.   This 

by  the  formula  Fa  =  Fi  y  gave  3-76  micros  (nearly)  as 

the  capacity  of  the  body.  In  taking  this  test  it  is  advisable 
that  the  observer  stands  as  far  from  the  subject  as 
possible. 


ANIMAL   AND   VEGETABLE  103 


Chapter  VII 

CELL   REPRODUCTION 

Mitotic  Division. — The  Centrosome  and  the 
Attraction  Sphere 

In    a    diagram    of    a  cell    (Schafer)  the    centrosome    is 
shown   double   and  lying  near   the   nucleus. 
This  is  a  minute  particle  (centriole),  surrounded 
by  a  clear  area  {attraction  sphere)  and  from  it 
radiate  into  the   surrounding  protoplasm    a 
number  of  fine  fibrils   and  dot-like   enlarge- 
ments  at   intervals.     The  twin   spheres    are 
connected  by    a  spindle-shaped  sj^stem  of  delicate  fibrils 
(achromatic  spindle),  and  this  duplication  invariably  precedes 
the  division  of  a  cell  into  two. 

In  the  process  of  division  of  a  cell  many  changes  occur 
but  it  is  always  "  preceded  by  the  division  of  its  attraction 
sphere,  and  this  again  appears  to  determine  the  division  of 
the  nucleus."     These  changes  are,  briefly,  as  follows  : — 

"  (1)  The  network  of  chromopl asm-filaments  of  the 
resting  nucleus  becomes  transformed  into  a  sort 
of  skein,  formed  apparently  of  one  long  convoluted 
filament,  but  in  reality  consisting  of  a  number  of 
filaments  (spirem) ;  the  nucleus  membrane  and 
the  nucleoli  disappear,  or  are  merged  in  the  skein. 

"  (2)  The  filament  breaks  into  a  number  of  separate 
portions,  often  V-shaped,  the  chromosomes.  .  .  . 
As  soon  as  the  chromosomes  become  distinct  they 
are  often  arranged  radially  round  the  equator  of 
the  nucleus  like  an  aster, 


104      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

"  (3)  Each  of  the  chromosomes  splits  longitudinally 
into  two. 

"  (4)  The  fibres  separate  into  two  groups,  the  ends  being 
for  a  time  interlocked,"  i.e.,  complete  division 
has  not  taken  place. 

"  (5)  The  two  groups  pass  to  the  opposite  poles  of  the 
now  elongated  nucleus  and  form  a  star-shaped 
figure  at  either  pole  (diaster).  Each  of  the  stars 
represents  a  daughter  nucleus,"  At  this  point 
complete  separation  has  occurred,  and  the  following 
appearance  is  presented  (Fig.  13) : — 


Fig.  13.  Fig.  14. 

"  (6),  (7),  (8).  Each  star  of  the  diaster  goes  through  the 
same  changes  as  the  original  nucleus,  but  in  the 
reverse  order,  viz.,  a  skein,  more  open  and  rosette- 
like, then  a  closer  skein,  then  a  network  ;  passing 
finally  into  the  typical  reticular  condition  of  a 
resting  nucleus. ' '  The  penultimate  stage  is  shown 
in  Fig.  14  and  is  the  stage  immediately  preceding 
the  division  of  the  cell. 

"  The  protoplasm  of  the  cell  divides  soon  after  the 
formation  of  the  diaster.  During  division  fine  lines  are 
seen  in  the  protoplasm,  radiating  from  the  centrosomes  at 
the  poles  of  the  nucleus,  whilst  other  lines  form  a  spindle- 
shaped  system  of  achromatic  fibres  within  the  nucleus, 
diverging  from  the  poles  towards  the  equator.  These  are 
usually  less  easily  seen  than  the  chromatic  fibres  or  chromo- 
somes, but  are  not  less  important,  for  they  are  derived  from 
the  attraction-spheres.  These  with  their  centrosomes 
alway  initiate  the  division  of  the  cell ;    indeed,  they  are 


ANIMAL  AND   VEGETABLE  105 

often  found  divided  in  the  apparently  resting  nucleus,  the 
two  particles  being  united  by  a  small  system  of  fibres  forming 
a    minute  spindle  at  one  side  of 

the    nucleus.     When    mitosis    is  ^-- ".-^ 

about  to  take  place  this  spindle         "'  "x 

enlarges,  and  as  the  changes  in        ' 

the    chromatin    of    the    nucleus       \ 

occur — which    changes     involve 

the  disappearance  of  the  nuclear  Fi'^is' 

membrane — the  spindle  gradually 

passes  into  the  middle  of  the  mitotic  nucleus,  and  with 

the  fibres  of  the  spindle  therefore  completely  traversing 

the  nucleus.     (Fig.  15.) 

"  The  spindle-fibres  appear  to  form  directing  lines,  along 
which  the  chromosomes  pass,  after  the  cleavage,  towards  the 
nuclear  poles  to  form  the  daughter  nuclei.''  * 

In  most  animal  cells  the  protoplasm  becomes  constricted 
into  two  parts  midway  between  the  two  daughter  nuclei* 
"  Each  daughter  cell  so  formed  retains  one  of  the  two 
attraction-particles  of  the  spindle  as  its  centrosome,  and 
when  the  daughter  cells  are  in  their  turn  again  about  to 
divide,  this  centrosome  divides  fii-st  and  forms  a  new  spindle, 
and  the  whole  process  goes  on  as  before."  (Schafer.) 

To  go  back  a  little,  to  the  properties  of  living  matter, 
we  learn  that  "  living  cells  exhibit  irritability  or  the  pro- 
perty of  responding  to  stimuli,"  electrical  or  otherwise, 
much  in  the  same  way  that  nerve  and  muscle  exhibit  it» 
and  I  think  we  can  postulate  it  as  almost,  if  not  quite, 
unanswerable  that  to  respond  to  electrical  stimulus  the 
structure  itself  must  be  to  some  extent  electrical.  That 
it  exhibits  irritability  under  mechanical,  chemical,  or 
thermal  stimuli  does  not  affect  the  question,  because  a 
stimulus  of  any  kind  must  disturb  the  equilibrium  of  an 
electrical  unit  of  so  delicate  and  sensitive  a  nature, 
*  The  italics  are  my  own. 


106      STUDIES  IN  ELECTRO-PHYSIOLOGY: 


It  now  remains  to  be  seen  whether  I  am  in  any  way 
justified  in  applying  the  term  "  electrical  unit  "  to  any 
animal  cell. 

Supposing  the  single  centrosome  to  be  an  electrified 
body,  no  electrical  action  of  attraction  or  repulsion  could 
take  place  within  it  while  it  remained  single, 
but  before  any  cell -reproduction  can  begin 
it  is  duplicated,  and  duplicated  in  a  very 
peculiar  form,  the  fibrils  having  dot-like 
enlargements  at  intervals. 

In  the  diagram  the  dark  spots  represent 

the  centrioles,  and  if,  as  I  imagine,  they 

are  bodies  similarly  electrified,  the  immedi- 

Fig.  16 .  ^^^  result  would  be  the  exercise  of  repulsion 

between  the  two,  and  consequent  elongation  of  the  cell. 

Dividing   the  centrioles  is  a  clear   space  over  which 

repulsion  would  first  be  exercised. 

In  Schafer  two  diagrams  are  given  to  illustrate  the 
changes  which  occur  in  the  centrosomes  and  nucleus  of  a 
cell  during  the  process  of  mitotic  division  : — 


^ 


3 


Fig.  17. 


Up  to  the  point  shown  in  A,  repulsion  seems  to  continue, 
and  we  are  told  that  "  the  spindle-fibres  appear  to  form 
directing  lines,  along  which  the  chromosomes  pass,  after 
the  cleavage,  towards  the  nuclear  poles  to  form  the  daughter 
nuclei."  It  would  seem,  however,  that  the  repulsive  force 
had  reached  its  limit  and  that  no  further  elongation  of  the 
cell    was  necessary,    because    at    an    intermediate    stage 


ANIMAL  AND   VEGETABLE  lOT 

between  A  and  B,  while  the  force  was  still  being  exerted, 
the  process  of  contracting  the  exoplasm  in  the  middle  in 
order  to  ensure  the  division  of  the  cell  at  that  point  must 
have  gone  on  ;  and  in  B  we  see  that  the  lines  of  force,  or 
the  spindle-fibres,  are  ceasing  to  exist.  That  being  so,  and 
the  cell  having  divided  into  two  parts,  each  with  its  nucleus, 
nucleolus,  and  single  centrosome,  it  prepares  itself  for 
renewed  growth  and  for  re-division. 

I  am,  of  course,  aware  that  the  chemical  changes  which 
take  place  are  all  important,  but  they  are  not  in  my  depart- 
ment, nor  am  I  qualified  to  deal  with  them.  I  am  en- 
deavouring, and  shall  continue  to  endeavour,  to  point  out 
that  the  structure  of  the  body  is  primarily  electrical,  and 
that  electrical,  or  neuro-electrical,  action  is  precedent  to 
chemical  change. 

And  when  we  know  more  about  their  precise  con- 
nections I  am  sure  we  shall  find  that  the  nucleus  and 
nucleolus  play  a  very  important  part  in  the  neuro-electrical 
scheme  of  cell-reproduction.  In  this  regard  I  should  like 
to  draw  the  attention  of  my  readers  to  that  section  of  this 
work  which  treats  of  ganglion  cells  in  their  electrical 
aspect,  and  would  further  observe  that  in  the  absence  of 
stimulus  or  excitement  the  amoeba  assumes,  and  with  it, 
I  take  it,  all  cells  assume,  a  form  more  or  less  spherical  or 
ovoid,  "  elongated,  annular,  or  irregularly  lobulated " 
(Halliburton),  which  in  a  condition  of  rest,  or,  in  other 
words,  prior  to  change,  is  their  natural  shape. 

It  will  be  seen  also  that  after  the  division  of  the  cell  has 
taken  place  the  single  centrosome 
(see  Fig.  18)  occupies  a  position  close 
to  the  nucleus.  In  that  state  it  is  at 
rest,  in  the  sense  that  the  nucleus 
is  at  rest.  When,  however,  the  time 
has  arrived  for  division  of  the  cell  to 
commence  the  centrosome  is  seen  as  in  ^^s-  is. 

Fig.  19, 


108      STUDIES   IN  ELECTRO -PHYSIOLOGY  : 

At  first  sight  one  might  be  inclined  to  think  that  its 
position  is  not  in  favour  of  the  hypothesis  I  have  advanced, 
because — if  the  diagram  correctly  represents  its  position, 
as  I  cannot  doubt  it  does — the  repulsive  force  would  be 
exerted  longitudinally,   and  in   such  case   would   merely 
elongate  that  portion  of  the  cell  to  the  right  of  the  nucleus. 
That  would  be  so  if,  immediately  the 
repulsive  force  begins  to  operate,  the 
nucleus  underwent  no  change.     But 
it    does    change.     The    network     of 
chromoplasm  filaments  of  the  resting 
nucleus  becomes  transformed  into  a 
p.     jg  sort  of  skein,  into  which  the  nuclear 

membrane  and  the  nucleoli  disappear. 
The   whole   cell,    with   the    exception   of    its    exoplasm, 
appears,  in  fact,   to  be  broken  up,   and  its   component 
parts   to  be  marshalled  into  order  by  the  centrosomes- 
But  in  what  manner  ?     If  the  broken- 
up  nucleus  was   between  the  attraction       ,*-'''  ""'*-., 
spheres,  as  shown  by  Schafer  (Fig.  20),  it    /' 
is  quite   evident  that  a   repulsive  force  / 
alone  would,  so  long  as  it  continued  to  be  '> 
exerted  and  for  so  long  as  the  disinteg- 
rated nucleus  had  no  polarity,  maintain  ------- 

the   substance   between   the    attraction  *^' 

spheres  at  the  same  distance  from  each  of  them.  It 
follows,  logically,  therefore,  that  if  in  the  process  of 
division  one  part  of  the  cell  cleaves  to  one  attraction 
sphere,  and  the  other  part  of  the  cell  to  the  other  attrac- 
tion sphere,  there  must  be  a  difference  of  polarity  between 
them. 

Suppose,  for  instance,  the  attraction  spheres  to  be 
similarly  electrified  and  to  repel  each  other,  so  that  they 
become  farther  apart,  with  a  certain,  non-electrified  (or 
^similarly  electrified  at  lower  tension)   substance  between 


ANIMAL  AND   VEGETABLE  109 

them.  Neither  the  nucleus  nor  the  nucleolus  is  non- 
electrified — of  that  I  am  sure— but  during  the  early  process 
of  division  the  nuclear  membrane  and  the  nucleoli  disappear 
or  are  merged  in  the  skein,  and,  inferential Ij^  lose  polarity 
for  the  time  being  by  loss  of  insulation  and  consequent 
diffusion.  The  moment,  however,  that  insulation  is  even 
partially  restored  polarity  would  come  into  play  ;  and 
reference  to  physiological  diagrams  makes  it  clear  that  at 
this  stage  of  division  the  two  attraction  spheres  and  the 
two  parts  of  the  nucleus  are  in  close  proximity,  each  with 
the  other. 

Assume  that  the  attraction  spheres  and  the  nucleus 
are  oppositely  electrified,  and  we  can  understand  why,  in 
the  first  place,  the  single  centrosome  lies  as  near  the 
nucleus  as  the  structure  of  the  cell  permits  ;  secondly, 
there  being  an  intervening  space  between  the  centrosomes, 
they  should  separate  at  that  part,  and  in  the  process  of  the 
nucleus  breaking  down  repel  each  other  until  they  form 
poles  at  opposite  ends  of  the  cell.  At  that  stage  the 
nucleus  would  be  in  a  condition  of  temporary  disintegration 
or  disarrangement,  but  as  its  insulation  returned  it  would 
regain  polarity,  and,  the  pull  being  exactly  equal,  we  can 
conceive  one-half  of  it  trending,  by  attraction,  to  the  left 
and  one-half  to  the  right  centrosome.  Equilibrium  would 
then  be  restored,  and  as  the  exoplasm  completed  the  circle 
around  each  of  the  daughter  nuclei,  or  rather  around  the 
protoplasm  surrounding  each  daughter  nucleus,  the  cell 
should  divide  by  constriction. 

I  will  endeavour  to  put  it  briefly.  In  its  condition  of 
rest,  or,  as  I  prefer  to  say,  of  development,  I  assume  the 
centrosome  and  nucleus  to  be  of  opposite  polarity.  Upon 
duplication,  the  two  centrosomes  move  to  extreme  ends 
of  the  cell.  The  moment  the  nucleus  loses  its  membrane, 
and  with  it  its  insulation,  it  becomes  similarly  electrified, 
the  chromosomes  exercise  a  repulsive  influence  upon  each 


110      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

other  under  the  control  by  the  lines  of  force  from  the 
centrosomes,  and,  being  in  multiples  of  two,  must  divide 
in  equal  numbers  at  the  equator.  So  soon,  however,  as  the 
two  sets  of  chromosomes  regain  insulation  they  again 
become  oppositely  electrified,  are  attracted  by  the  centro- 
somes, and  form  two  equal  groups. 

Segmentation  of  the  Ovum. 

Usually,  it  is  said,  the  two  daughter  cells  are  of  the 
same  size,  but  this  is  not  so  in  the  case  of  the  ovum,  which, 
before  fertilisation,  divides  twice  (by  hetero-  and  homo- 
typical  mitosis  respectively)  "  into  two  very  unequal 
parts,  the  larger  of  which  retains  the  designation  of  ovum, 
while  the  two  small  parts  which  become  detached  from  it 
are  known  as  the  polar  bodies.  Further,  in  the  formation 
of  the  second  polar  body  a  reduction-division  occurs,  and 
the  nucleus  of  the  ovum,  after  the  polar  bodies  are  ex- 
tended, contains  only  one-half  the  number  of  chromosomes 
that  it  had  previously — e.g.,  twelve  in  place  of  the  normal 
twenty-four  in  man,  and  two  instead  of  four  in  Ascaris 
Megalocephala  (var.  bivalvens).  Should  fertilisation  super- 
vene, the  chromosomes  which  are  lacking  are  supplied  by 
the  male  element  (sperm-cell),  the  nucleus  of  which  has 
also  undergone,  in  the  final  cell-division  by  which  it  was 
produced,  the  process  of  reduction  in  the  number  of 
chromosomes  to  one-half  the  normal  number.  The  two 
reduced  nuclei — which  are  formed  respectively  from  the 
remainder  of  the  nucleus  of  the  ovum  after  extrusion  of  the 
polar  bodies,  and  from  the  head  of  the  spermatozoon, 
which  contains  the  nucleus  of  the  sperm-cell — are  known 
(within  the  ovum)  as  the  sperm  and  germ  nuclei,  or  the 
male  and  female  pronuclei.  When  these  blend,  the  ovum 
again  contains  a  nucleus  with  the  number  of  chromosomes 
normal  to  the  species."     (Schafer.) 

It  will  thus  be  seen  that  while  the  process  of  division 


ANIMAL  AND   VEGETABLE 


111 


of  the  ovum  is  more  complicated  than  that,  for  instance, 
of  various  kinds  of  somatic  cells,  it  obeys  the  same  law  of 
alternate  repulsion  and  attraction. 

This  may  be  more  readily  comprehended  by  study  of 
the  fertilisation  and  fii'st  division  of  the  ovum  of  the  worm 
Ascaris  Megalocephala,  owing  to  the  comparative  simplicity 
of  the  structure  and  the  smaller  number  of  chromosomes. 

To  put  it,  if  I  can,  a  little  less  technically  than  Schafer, 
the  ovum  first  discharges  or  extrudes  from  its  interior  two 
portions  of  its  nucleus,  which  form  globules  upon  the  ovum 
and  are  called  the  polar  bodies.  These  appear  to  play  the 
same  part  as  the  centrosomes  and  attraction  spheres  in 
ordinary  mitosis,  and,  disregarding  for  the  moment  the 
fusion  of  the  male  and  female  pronuclei,  the  penultimate 
stages  of  segmentation  of  the  ovum,  as  shown  by  Schafer, 
differ  in  no  important  respect  from  those  of  mitotic  divi- 
sion. Those  stages  are  illustrated  in  the  following 
manner  : — 


A.  Fig.  21. 
Ascaris  Megalocephala. 
A. — Mingling  and  splitting  of 
the  four  chromosomes  (c) ;  the  ach- 
romatic spindle  is  fully  developed, 
but  division  of  the  cytoplasm  has 
not  yet  commenced. 


B.  Fig,  22. 
B. — Separation  (towards  the 
poles  of  the  spindle)  of  the  halves 
of  the  split  chromosomes,  and  com- 
mencing division  of  the  cytoplasm. 
Each  of  the  daughter  cells  now  has 
four  chromosomes  ;  two  of  these 
have  been  derived  from  the  ovum 
nucleus,  two  from  the  spermatozoon 
nucleus. 


The  extrusion  of  the  polar  bodies  may  be  readily  under- 
stood. We  know  that  (1)  like  electricities  repel  one 
another,  (2)  unlike  electricities  attract  one  another,  and 


112       STUDIES  IN  ELECTRO-PHYSIOLOGY: 

(3)  the  force  of  attraction  or  repulsion  varies  inversely  as 
the  square  of  the  distance  between  the  two  electrified 
bodies,  and  directly  as  the  amount  of  the  charge  of  the  two 
bodies. 

We  are  also  aware  that  one  of  the  earliest  changes  to 
occur  in  mitosis  and  in  segmentation  is  the  breaking  up  of 
the  nuclear  membrane.  Assume,  then,  that  the  nucleus  is 
an  electrified  body  and  that  those  portions  of  it  which 
become  the  polar  bodies  are  the  first  to  detach  themselves 
or  be  detached  from  it,  and  the  process  of  extrusion  (by 
repulsion)  becomes  clear.  We  are  also  entitled  to  believe 
that  their  amount  of  charge  is  exactly  equal,  and  have 
seen  that  the  chromosomes  are  always  in  multiples  of  two. 
That  being  so,  the  latter  should,  upon  regaining  some 
measure  of  their  insulation,  trend  towards  the  polar  bodies 
(by  attraction)  in  two  groups  of  equal  numbers. 

In  plant  life  sexual  reproduction  is  first  found  in  the 
form  of  conjugation,  as  in  mucor  and  spirogyra,  where  the 
male  and  female  elements  are  similar  in  shape  and  size.  They 
are  simple  cells,  and  fuse  together  to  produce  a  zygospore. 
"  Fucus  exhibits  sexual  production  alone,  and  that  in  a 
very  typical  manner.  Male  and  female  organs,  in  this  case 
trichomes,  are  present,  which  produce  respectively  small 
motile  male  cells,  spermatozoids,  and  passive,  relatively 
\BXge  female  cells,  the  oospheres.  One  male  cell  fuses  with 
each  female  cell,  which  is  now  fertilised,  and  can  develop 
into  a  new  plant."     (Davis.) 

The  phenomena  presented  by  sexual  or  asexual  repro- 
duction appear  to  be  common  to  all  forms  of  animal  and 
vegetable  life,  from  the  lowest  to  the  highest.  The  presence 
of  nuclei  has  been  demonstrated  in  the  vegetative  and 
reproductive  parts  of  fungi  belonging  to  widely  separated 
orders,  and  Schizomycetes  are  of  the  class  of  fungi  and 
require  organic  matter  as  food  ;  in  diatomacese  and  in 
protozoa  ;  and  I  have  little  doubt  that  if  a  sufficiently  high 


ANIMAL   AND   VEGETABLE  113 

power  could  be  used  bacteria  would  be  seen  to  be  mostly 
multicellular  organisms  which,  by  division  and  sub- 
division, proliferate  themselves  in  much  the  same  way  as 
some  of  the  species  of  confervoideae. 

"  In  all  probability,"  remarks  Massee,  in  The  Evolution 
of  Plant  Life,  "  nuclei  in  a  primitive  state  of  differentiation 
are  present  in  all  plant  cells.  The  exact  function  of  the 
nucleus  is  not  known,  but  judging  from  its  almost  universal 
occurrence,  and  its  behaviour  in  connection  with  the 
formation  of  new  cells,  it  must  be  supposed  to  perform 
some  important  function." 

With  that  view  we  must  all  be  in  agreement.  Without 
the  nucleus  cell-reproduction  could  not  occur. 

If  that  is  so,  however,  and  we  suppose  bacteria  to 
multiply  themselves  by  the  exercise  of  some  electro- 
chemical function,  we  must  draw  a  line  of  demarcation 
between  aerobic  and  anaerobic  micro-organisms.  The 
former  need  only  contain  some  substance  electro-positive 
to  oxygen  for  electrical  action  to  occur,  whereas  the 
latter  should  be  self-contained  ;  that  is  to  say,  they  should 
be  provided  with  both  positive  and  negative  materials, 
requiring  only  suitable  liquid  to  excite  them. 

Those  who  doubt  the  existence  of  a  network  in  proto- 
plasm would  do  well  to  examine,  for  example,  the  naked 
protoplasm  of  a  myxogaster  (a  yellow-coloured  saprophyte, 
generally  met  with  on  decaying  wood),  and  the  structure  of 
a  grain  of  wheat  and  of  rice,  with  special  regard  to  the 
arrangement  and  insulation  of  the  starch  cells.  The  same 
phenomenon,  in  a  modified  form,  will  be  observed  ;  and 
if  vegetable  and  animal  physiology  were  always  studied 
together  many  other  doubts  and  perplexities  might  be 
resolved. 

I  am  not  concerned  with  enzyme  action  in  its  chemical 
aspect,  but  certain  facts  in  connection  with  it  are  not 
without  significance.     The  action  is  intracellular  ;    a  rise 

I 


114      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

of  temperature  has  much  the  same  effect  upon  enzymes 
as  it  has  upon  the  velocity  of  the  nerve  impulse,  they  die 
at  much  the  same  temperature  as  protoplasm,  and  their 
activity  is  checked  or  destroyed  by  many  of  the  chemical 
substances,  such  as  strong  acids  and  alkalis  which  check 
or  destroy  amoebic  movement.  This  proves  nothing,  but 
it  opens  the  door  to  the  suggestion  that  enzyme  action, 
instead  of  being  wholly  chemical,  may  be  in  some  measure 
electrical. 

The  best  description  of  cell-division  in  plants  is  given 
by  Professor  Vines  in  his  Text-hook  of  Botany.  He  says : 
"  The  indirect  division  of  the  nucleus  presents  a  series  of 
remarkable  phenomena  which  are  collectively  designated 
by  the  term  karyokinesis.  Beginning  with  the  nucleus  in 
the  resting-state,  the  first  fact  indicating  the  imminence  of 
nuclear  division  is  that  the  two  centrospheres  "  (centro- 
somes)  "  separate  and  take  up  positions  on  opposite 
sides  of  the  nucleus,  thus  indicating  the  plane  in  which  the 
nuclear  division  is  to  take  place,  viz.,  at  right  angles  to  a 
straight  line  joining  the  centrospheres  :  the  change  of 
position  of  the  centrospheres  is  doubtless  effected  by  the 
kinoplasm  in  which  they  lie.  Changes  are  now  perceptible 
in  the  nucleus  itself.  The  fibrillar  network  contracts  and 
becomes  more  dense,  and  breaks  into  distinct  fibrils  (chromo- 
somes) consisting  now  of  broad  discs  of  chromatin  with 
narrower  intervening  discs  of  linin ;  the  tangle  of  the 
somewhat  V-shaped  fibrils  becomes  looser  as  they  separate 
and  move  towards  the  surface  of  the  nucleus.  At  this  stage 
the  so-called  nuclear  membrane  loses  its  definiteness,  the 
kinoplasm  entering  the  nucleus  without,  however,  dis- 
placing the  proper  ground-substance  of  the  nucleus.  The 
kinoplasm  forms  a  number  of  threads,  extending  from  one 
centrosphere  to  the  other,  constituting  the  kinoplasmic 
spindle  "  (achromatic  spindle),  "  of  which  the  centrospheres 
are  the  two  poles.     Along  these  threads  the  fibrils  move 


ANIMAL  AND   VEGETABLE  115 

till  they  reach  the  equatorial  plane  of  the  spindle,  where 
they  constitute  the  nuclear  disc,  and  are  so  placed  that 
their  free  ends  point  to  either  one  pole  or  the  other.  Whilst 
these  changes  have  been  going  on,  the  nucleoli  have  dis- 
appeared, being  diffused  in  the  nuclear  ground-substance. 
The  fibrils  now  undergo  longitudinal  splitting  into  two, 
and  then  the  nuclear  disc  separates  into  two  halves,  in  such 
a  way  that  one  of  each  pair  of  fibrils  produced  by  the 
splitting  of  each  primary  fibril  goes  to  each  half.  The 
fibrils  constituting  each  half  of  the  nuclear  disc  now  move 
towards  the  corresponding  pole  along  the  spindle-threads, 
changing  their  position  as  they  go,  so  that  when  they 
reach  the  pole  their  free  ends  point  towards  the  equatorial 
plane.  On  reaching  the  pole,  each  group  of  fibrils  con- 
stitutes a  new  nucleus  ;  it  becomes  invested  by  a  mem- 
brane, nucleoli  reappear,  and  the  fibrils  resume  the  form 
and  structure  of  the  resting  nucleus.  The  two  nuclei  are 
now  completely  formed,  and  are  still  connected  by  kino- 
plasmic  spindle-threads  "  (as  in  Fig.  17).  "  If  no  cell- 
division  is  immediately  to  take  place,  no  further  change 
occurs  beyond  the  disappearance  of  the  threads,"  and  this, 
it  will  be  noted,  is  the  stage  immediately  preceding  division 
in  ordinary  mitosis. 

It  is  interesting  to  compare  this  account  of  vegetable 
cell -reproduction  with  that  given  by  Schafer  of  mitotic 
division  of  the  animal  cell.  The  wording  is  different,  but 
the  processes  appear  to  be  identical. 


116      STUDIES  IN  ELECTRO-PHYSIOLOGY: 


Chapter   VIII 


ANIMAL    MAGNETISM 


For  more  than  a  century  we  have  heard  of  "  Animal 
Magnetism,"  and  even  some  modern  scientific  men — 
Professor  Rosenthal  amongst  the  number — are  inclined  to 
attribute  certain  vital  phenomena  to  magnetic  influences 
contained  in  the  body. 

The  temptation  to  do  so  is  great  because  some  points 
of  resemblance  may  be  found,  but  the  view  is  a  fallacious 
one,  as  I  will  endeavour  to  show. 

Inasmuch  as  we  do  not  know  what  the  force  called 
magnetism  is,  I  do  not  propose  to  discuss  it  further  than  is 
necessary.  In  the  course  of  nearly  forty  years  of  research 
work  I  have  not  been  able  to  find  any  evidence  of  its 
existence   in   the   human   body.     Superficially,    however. 


Fig.  23. 

certain  phenomena  may  appear  to  be  due  to  magnetic 
control. 

As  instances  of  this  we  may  take  mitotic  division  and 


ANIMAL  AND   VEGETABLE 


117 


the  segmentation  of  the  ovum,  which,  as  we  have  seen, 
permit  of  another  and  more  reasonable  explanation. 

In  a  work  called  The  Evolution  of  Sex,  by  Geddes  and 
Thomson,  the  illustration  on  preceding  page  is  given  of  cell- 
division,  suggesting  the  internal  disruptions  and  rearrange- 
ments of  the  nucleus  and  protoplasm. 

Let  us  compare  that  with  the  lines  of  force  of  a  bar 
magnet. 


te.: :•-.•?  ■  •■: ■  •.  -.-  ■! ■■."'/'Am 


^:^ 


Fig.  24. 

There  is  a  quite  remarkable  similarity.  We  will, 
however,  instead  of  one,  take  two  bar  magnets  and  arrange 
them  thus  and  with  this  result  :— 


Fig.  25. 

They  would  repel  each  other  ;  the  space  between  the 
two  might  be  called  the  achromatic  spindle  and  the 
magnets  themselves  the  centrosomes.  But  we  should  have 
precisely  the  same  result  if  for  the  magnets  we  substituted 
two  similarly  electrified  bodies. 

All  the  body  phenomena  can  be  readily  and,  I  believe, 
correctly  explained  in  the  same  way,  by  the  law  of  electrical 
attraction  and  repulsion,  both  as  regards  intra-  and  extra- 
cellular control,  and  to  the  best  of  my  knowledge  there  is 
no  such  thing  as  animal  magnetism. 


118      STUDIES  IN  ELECTRO-PHYSIOLOGY: 


Chapter   IX 
SOME    EVIDENCES    OF    THE    LAW 

ANIMAL  VEGETABLE 


Fig.  26. 

One  of  the  phases  of  the  nuclear 
chromatin  filaments  in  the  process 
of  ordinary  mitosis  of  the  somatic 
cell.    (ScMfer.) 


Fig.  27. 

One  of  the  changes  of  the  cell- 
nucleus  during  division  (Allium 
odorum).    {After  Sachs.) 


Fig.  28. 

Epithelium-cells  of  salamandra 
larva  in  different  phases  of  division 
by  mitosis.    {Sckafer.) 


Fig.  29. 

Changes  in  the  cell-nucleus  during 
the  division  of  the  mother-cell  of  a 
stoma  of  Iris  pumila.  {After  Stras- 
hurger.) 


ANIMAL  AND   VEGETABLE 


119 


ANIMAL 


ex 


Fis.  SO. 


Diagram  of  a  cell. — p,  proto- 
plasm ;  n,  nucleus  ;  n\  nucleolus  ; 
c,  double  centrosome ;  ex,  exo- 
plasm.  (After  Schafer.) 


VEGETABLE 


/?' 


''^^^'^^^S^^JgiSiK 


Fig.  31. 

Young  pollen-grain  of  Lilium 
Martagon,  showing,  c,  double  con- 
trosphere ;  n,  resting  nucleus ; 
n^,  nucleolus  ;  p,  protoplasm. 
{After  Guignard.) 


Fig.  32. 

Diagram  showing  a  change  in 
the  centrosomes  and  nucleus  of  a 
cell  in  the  process  of  mitotic  divi- 
sion. The  nucleus  is  supposed  to 
have  four  chromosomes.  {After 
Schafer.) 


Fig.  33. 

Germinating  pollen-grain  of  Li- 
lium Martagon  with  dividing  nu- 
cleus :  the  kinoplasmic  spindle  is 
formed  with  a  centrosphere  at  each 
pole  ;  ti  is  the  nuclear  disc  formed 
by  the  chromosomes.  (After 
Guignard.) 


Fig.  34. 

Fertilisation  of  the  ovum  by  the 
spermatozoon  (of  a  mammal). 
(4fter  Haeckel). 


Fig.  35. 

Oosphere,    with    spermatozoids. 
(After  Strasburger.) 


120      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

The  foregoing  may  be  considered  as  direct  evidences  of 
the  universality  of  the  law  which  governs  all  living  things. 
The  examples  I  am  about  to  cite  cannot  be  said  to  fall, 
without  question,  into  this  category,  because  while  the 
structures  exhibit  a  striking  resemblance,  the  organs  are 
not  in  all  cases  designed  for  the  same  purpose  or  function. 
A  little  reflection,  however,  will  show  that,  so  far  as  structure 
is  concerned,  it  differs  only  in  detail,  in  more  or  less  perfec- 
tion of  finish  or  development ;  the  underlying  principle  is 
there.  Let  us  call  them  coincidences  for  the  time  being, 
and  trust  to  future  investigation  to  link  them  in  some 
measure  more  closely  together.  It  may  here  be  said  that 
only  from  the  "  living  "  can  any  reversal  of  sign,  implying 
an  electrical  system,  be  obtained.  In  the  "  non-living  '' 
there  is  no  difference  of  potential  unless  introduced  by 
some  exterior  vehicle  of  energy. 


ANIMAL 


VEGETABLE 


Fig.  36. 
Ganglion  cell  with  nerve  process 
(human). 


Fig.  37. 

Original  spore  of   Vaucheria  Ses- 
silis.     (After  Sachs.) 


Section  of  spinal  cord  (human). 
(After  Schafer.) 


Fig.  39. 

Diagrammatic  sketch  of  trans- 
verse section  through  portion  of 
root  of  Phaseolus  multiflorus,  (After 
Sachs.) 


ANIMAL  AND  VEGETABLE 
ANIMAL  VEGETABLE 


121 


Fig.  40. 

Unipolar  cell   from  spinal   gan- 
glion of  rabbit.     (After  ScMfer.) 


Fig.  42. 

A.  Spiral  and  reticular  fibrils 
in  the  sheath  of  a  nerve-fibre. 

B.  Reticular  appearance  in  the 
medullary  sheath  of  a  nerve-fibre. 
(Schafer.) 


Fig.  41. 

Vsnea  barbata.  Transverse  sec- 
tion of  a  branch  :  r,  epidermal 
layer  ;  m,  fundamental  tissue  ;  x, 
axial  strand.     (After  Sachs.) 


^ 


jB 


^ 


■S 


Fig.  43. 
from  a   leaf 


of  Hoya 


A.     Cells 
Carnosa. 

A.  External  view  of  the  side 
where  the  annular  striae  cross. 

B.  Portion  of  an  annular  vessel 
from  the  fibro-vascular  bundle  of 
Zea  Mays.    (After  Sachs.) 


The  main  differences  between  the  two  sets  of  figures 
appear  to  be  due  to  the  absence  of  blood-vessels  in  the 
vegetable  sections  ;  although  there  seems  to  be  a  pro- 
vision for  the  circulation  of  sap  in  the  latter. 


122      STUDIES  IN  ELECTRO-PHYSIOLOGY: 
ANIMAL  VEGETABLE 


Fig.  44. 

Formation  of  blastoderm  in  rab- 
bit by  division  of  ovum  into  a 
number  of  cells. 

A.  During  formation  of  "  mul- 
berry mass."     (Schdfer.) 


3 

Fig.  45. 

Athcea   rosea ;    division    of    the 
pollen    mother-cells . 

B.    A  stage  thereof .  {After  Sachs.) 


Fig.  46. 

A  group  of  cartilage-cells  showing 
the  capsular  outlines  in  the  matrix 
surrounding  the  group.     (Rantner.) 


Fig.  47. 

The  same,  in  a  shghtly  different 
form,  as  the  above. 


Fig.  48. 

Part  of  a  transverse  section 
the  sciatic  nerve  of  a  cat. 


Fig.  49. 

of  A    parenchyma    cell    from    the 

cotyledon  of  Phaseolus  muUiflorus. 
(After  Sachs.) 


ANIMAL  AND  VEGETABLE       123 
ANIMAL  VEGETABLE 


Fig,  50. 

Two  white  fibro-cartilage  cells 
from  an  intervertebral  disk  (hu- 
man).   (Schafer.) 


Fig.  51, 

Two  thickened  cells  from  the 
cortical  tissue  of  the  stem  of  Lyco- 
podium  chamcccyparissus.    (Sachs.) 


Fig.  52, 

From  a  section  through  a  salivary 
gland  (human),  (After  Noble 
Smith.) 


Glandular  colleter  from  a  stipule 
of  Viola  tricolor.  (After  Stras- 
burger.) 


Fig.  54. 

Muscular  fibre-cell  from  the  small 
intestine  (human).     (After  Schafer.) 


Fig.  55. 

A  sclerenchymatous  fibre  (vege- 
table).    (After  Strasburger.) 


124      STUDIES  IN   ELECTRO-PHYSIOLOGY: 


ANIMAL 


VEGETABLE 


Fig.  56. 
Diagrammatic  frontal  section  of 
the  pregnant  human  womb.   {After 
Haeckel.) 


Fig.  57. 

Ovule  of  a  gymnosperm  in 
longitudinal  section.  {After 
Sachs.) 


Fig.  58. 

Epithelium-cells  of  Descemet's 
membrane.  {After  Smirnow  and 
Nu'el.)    iScMfer.) 


Portion  of  the  peripheral  proto- 
plasm of  the  embryo-sac  of  Reseda 
odorata.     {After  Strasburger .) 


ANIMAL  AND  VEGETABLE 


125 


ANIMAL 


VEGETABLE 


Fig.  60. 

Endothelium  of  a   serous  mem- 
brane (human).     {After  Schdfer.) 


Fig,  61. 

Cells  from  a  tendril  of  Cucurbita 
pepo.     {After  Strasburger.) 


Fig.  62. 

Section  across  a  nerve  bundle  in 
the  second  thoracic  anterior  root 
of  the  dog.     {After  Gaskell.) 


Fig.  63. 

Transverse  section  through  a 
young  internode  of  the  shoot  axis 
of  Tradescantia  albiflora.  {After 
De  Bary.) 


126       STUDIES  IN  ELECTRO-PHYSIOLOGY: 
ANIMAL  VEGETABLE 


Fig.  64.  Fig.  65. 

Network  of  capillary  vessels  of  Laticiferous  vessels  from  a  see- 
the air-cells  of  the  horse's  lung.  tion  through  the  root  of  Scorzonera 
(After  Frey.)  hispanica.    (After  Sachs.) 


Laticiferous    Vessels. 

The  resemblance  of  laticiferous  to  blood-vessels  is 
remarked  by  Sachs.  He  says  :  "  The  laticiferous  vessels 
themselves  are  always  so  narrow  that  they  can  never  be 
seen  on  a  transverse  section  of  the  organ  with  the 
unaided  eye.  The  microscope,  however,  shows  that 
they  may  be  of  very  different  diameter  in  the  same 
plant.  In  the  roots,  shoot-axes,  and  nerves  of  the  leaves, 
run  thicker  tubes,  from  which  thinner  and  yet  thinner 
ones  arise.  The  substance  of  the  walls  of  the  tubes  always 
consists  of  soft  cellulose,  sometimes  capable  of  swelling  ; 
they  are  never  lignified,  suberised,  or  otherwise  essentially 
altered  by  infiltration.  One  of  the  most  prominent 
characteristics  of  the  laticiferous  vessels  is  their  continuity 
throughout  the  whole  plant,  or  at  any  rate  over  wide  areas. 
This  may  obviously,  even  if  not  in  every  point,  be  closely 
compared  with  the  vascular  system  of  an  animal.  .  .  . 


ANIMAL  AND   VEGETABLE 


127 


If  it  were  possible  by  any  means  to  destroy  all  the  other 
tissues  of  such  a  plant  as  a  large  Euphorbia  or  Asclepias, 
the  entire  form  of  the  plant  would  still  be  preserved  as  a 
mass  of  very  fine  threads  of  various  thickness,  representing 
the  ramifications  of  the  original  latex-cells  ;  just  as  the 
injected  vascular  system  of  a  vertebrate  animal  after  the 
removal  of  all  other  tissue  allows  the  whole  organisation  of 
the  body  to  be  recognised.  .  .  .  The  laticiferous  vessels 
contain  two  essentially  different  groups  of  substances : 
those  which  are  again  utilised  in  metabolism  (proteids, 
carbo-hydrates,  fats,  ferments),  and  those  which  must  be 
regarded  as  excreta  useless  in  metabolism  (resins,  gums, 
alkaloids,  etc). 


ANIMAL 


VEGETABLE 


Fig.  66. 

Injected  blood-vessels  of  a  human 
muscle.  {After  Landois  and  Stir- 
ling.)   (KoUiker.) 


Fig.  67. 

Section  from  Scorzonera  his- 
panica  showing  reticulately  united 
latex  vessels.     {After  Strasburger.) 


"  The  green  vegetables  are  particularly  rich  in  salts, 
which  resemble  the  salts  of  the  blood  ;  thus,  dry  salad  is 
said  to  contain  twenty-three  per  cent,  of  salts,  which 
closely  resemble  the  salts  of  the  blood." 

Given  the  necessary  patience,  I  have  no  doubt  that 


128      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

many  other  examples  could  be  found,  but  the  foregoing 
should  be  in  themselves  sufficient  to  establish  the  point  I 
have  been  endeavouring  to  make. 

Unfortunately  it  is  not  always  possible  to  find  parallel 
illustrations,  but  I  may  take  the  opportunity  afforded  by 
this  chapter  to  give  the  views  of  some  authorities  upon 
points  of  resemblance  between  animal  and  vegetable 
organisms.  In  Vegetable  Physiology,  by  J.  R.  Green, 
F.R.S.,  I  find  the  following  :  "  If  we  turn  to  the  reaction 
of  the  leaf  of  the  Dionoea  to  contact,  we  find  that  the  whole 
leaf  may  be  somewhat  roughly  handled  without  closing, 
so  long  as  no  contact  is  made  with  the  hairs,  three  in 
number,  which  arise  on  a  particular  portion  of  the  blade. 
So  soon,  however,  as  one  of  these  is  touched,  the  leaf  closes. 

"  It  is  impossible  to  avoid  the  conclusion  that  we  have 
to  do  in  these  instances,  which  are  only  representative 
ones,  with  a  localisation  of  sensitiveness,  or  the  differentia- 
tion of  sense-organs.  .  .  .  The  power  of  sight  is  very 
complete  in  the  higher  animals  .  .  .  but  in  the  lower 
animals  it  becomes  less  and  less  perfect,  till  in  some  it  goes 
probably  little  further  than  the  power  of  appreciating  light. 
This  power  we  have  seen  to  be  possessed  by  certain  parts 
of  the  young  seedlings  of  various  plants  in  a  very  high 
degree,  and  by  other  organs  to  a  less  extent.  The  sense  of 
touch  may  be  compared  with  the  power  of  responding  to 
the  stimulus  of  contact  shown  by  tendrils  and  by  the  tips 
of  roots  ;  the  muscular  sense,  or  power  of  appreciating 
weight,  is  perhaps  comparable  to  the  property  of  respond- 
ing to  the  attraction  of  gravitation,  while  the  chemotactic 
behaviour  of  certain  organisms  suggests  a  rudimentary 
power  of  taste  or  smell,  or  both.  ...  If  we  turn  to  a 
second  feature  of  the  nervous  system,  we  find  that  the 
motor  mechanism  of  the  plant  seems  at  first  to  be  entirely 
different  from  that  of  the  animal.  Closer  consideration, 
however,  lessens  the  difference  considerably.     The  motor 


ANIMAL   AND   VEGETABLE 


129 


mechanism  of  an  animal  is  very  largely  either  muscular  or 
glandular.  The  contractile  power  is  but  little  developed 
in  vegetable  protoplasm,  and  when  present  it  seems  to  be 
rather  passive  than  active,  to  produce  frequently  recoil 
rather  than  true  contraction.  Still,  the  latter  is  not 
entirely  absent.  .  .  .  Though  the  power  of  contraction  is 
comparatively  seldom  found,  it  has  its  representative  in 
the  power  which  vegetable  protoplasm  possesses  of  resisting 
or  assisting  the  transit  of  water.  .  .  .  The  main  require- 
ment of  most  animals  is  freedom  of  locomotion  or  rapid 
assumption  by  the  body  of  new  positions.  The  most 
important  duty  of  the  plant  is  the  regulation  of  the  water 
supply  upon  which  its  constituent  protoplasts  are  so 
dependent."  This  is  chiefly,  if  not  entirely,  accomplished 
by  means  of  the  stomata  upon  the  under  surface  of  the 
leaves,  which  open  or  close  in  accordance  with  the  require- 
ments of  the  plant.  Three  of  these  are  shov/n  in  the 
following  figure  : — 


zrdCe^ 


Fig.  08. 

Surlace   v'lew  oi  part  of  the  under  surface  ot  a  icaf,  sho\\'ing  three 
stomata  in  different  stages  of  opening  and  closing.     {After  Green.) 

"  The  effects  of  stimulation  may  be  seen  in  glandular 
organs  in  plants  as  well  as  animals.     Both  Drosera  and 


130       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

Dioncea  are  excited  by  contact  to  pour  out  on  to  the  surface 
of  their  leaves  acid  digestive  secretions,  which  are  the 
result  of  changes  in  the  activity  of  the  gland-cells. 

'*  The  conduction  of  the  stimuli  received  is  due  in 
animals  to  the  existence  of  differentiated  nerves.  The 
way  in  which  it  is  carried  out  in  plants  has  been  much 
debated,  but  since  the  discovery  of  the  continuity  of  the 
protoplasm  through  the  cell-walls  there  ^is  little  doubt 
that  we  have  here  a  similar  mechanism.  .  ,  .  Though 
there  is  no  particular  differentiation  of  an  anatomical 
character  in  any  of  the  sense-organs  of  a  plant,  there  is 
nevertheless  a  differentiation  of  a  physiological  nature  in 
the  direction  of  sensitiveness,  which  v/ill  equal  if  not  surpass 
the  powers  of  the  sense-organs  of  an  animal.  The  tendril 
of  Passiflora  appreciates  and  responds  to  a  pressure  which 
cannot  be  detected  by  even  the  human  tongue ;  the 
seedlings  of  Phalaris  readily  obey  the  stimulus  of  an 
amount  of  light  which  is  hardly  perceptible  to  the  human 
eye.  Many  plants  readily  detect  and  respond  to  the  ultra- 
violet rays  of  the  spectrum,  v>'hich  are  utterly  invisible 
to  man." 

In  his  thirty-fourth  lecture.  General  Considerations  of 
Irritability,'^  Sachs  said  :  "  Returning  from  these  general 
considerations  to  definite  comparisons  between  the  animal 
and  the  plant,  I  would  make  special  mention  of  that 
exceedingly  remarkable  phenomenon  in  animal  life,  termed 
by  its  great  discoverer,  Johannes  Miilier,  the  specific 
energies  of  the  sensory  nerves.  As  is  well  known,  we 
understand  by  this  fact  that  for  instance  the  optic  nerve 
responds  to  any  given  excitation  whatever  with  the  sensa- 
tion of  light  :  true,  this  sensation  is  as  a  rule  called  forth 
by  the  vibrations  of  the  luminiferous  ether,  but  even 
electric  currents  or  mere  concussion  or  diseased  conditions 
impel  the  optic  nerve  to  the  sensation  of  light.     In  the 

*  The  Physiology  of  Plants. 


ANIMAL  AND   VEGETABLE  181 

same  way  the  auditory  nerve  is  impelled  to  the  perception 
of  sound,  not  merely  by  waves  of  sound,  but  by  every 
change  which  affects  it,  and  similarly  with  the  remaining 
organs  of  sense. 

"  Now  I  pointed  out  years  ago  that  even  the  organs  of 
plants  are  provided  with  similar  specific  energies.  Irritable 
organs  in  plants  are,  indeed,  like  the  sense-organs  of 
animals,  sensitive  to  a  definite  category  of  stimuli,  but 
they  can  very  often  be  affected  by  other  stimuli  also,  and 
in  this  case  the  stimulation  is  always  the  same.  This 
appears  most  distinctly,  for  example,  in  the  case  of  growing 
internodes  and  leaves.  If  they  are  illuminated  from  one 
side  they  become  curved,  and  if  brought  out  of  their 
normal  position  they  are  caused  to  make  exactly  similar 
curvatures  :  the  one  mode  possible  for  responding  to  any 
stimulus  whatever  is  simply  this  curving.  The  matter 
only  obtains  its  full  significance  by  the  fact  that  every 
individual  plant-organ  responds  to  the  influence  of  light  as 
well  as  to  that  of  gravitation  in  a  manner  specifically 
peculiar  to  it,  and  it  is  upon  this  that  the  anistropy  of  the 
parts  of  plants  depends.  No  less  clear  is  the  specific 
energy  of  tendrils.  .  .  .  The  identity  of  the  effect  of 
stimulation  in  cases  where  totally  different  stimuli  act  on 
the  growing  root-tips  is  particularly  striking.  .  .  .  The 
organ  possesses  only  one  mode  of  responding  to  stimuli  of 
the  most  various  kinds.  .  .  .  The  organism  itself  is  only 
the  machine,  consisting  of  various  parts,  and  which  must 
be  set  in  motion  by  the  action  of  external  forces  :  it  de- 
pends upon  its  structure  what  effects  these  external  forces 
produce  in  it. 

"  It  would  betray  a  very  low  level  of  scientific  culture 
to  see  in  this  comparison  a  degradation  of  the  organism, 
since  in  a  machine,  although  only  constructed  by  human 
hands,  there  lies  the  result  of  the  most  profound  and  care- 
ful thought  and  high  intelligence,  so  far  as  its  structure  is 


132       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

concerned,  and  in  it  there  subsequently  become  effective 
the  same  forces  of  Nature  which  in  other  combinations 
constitute  the  vital  forces  of  an  organ.  .  .  .  We  are 
warranted  in  regarding  the  so-called  spontaneous  or 
independent  periodic  movements  "  (in  plants)  "  as  phe- 
nomena of  irritability,  just  as  animal  physiologists  place 
the  periodic  pulsations  of  the  heart  in  the  series  of  phe- 
nomena of  animal  irritability.  ...  I  have  repeatedly  had 
cause  to  refer  to  certain  resemblances  between  the  phe- 
nomena of  irritability  in  the  vegetable  kingdom  and  those 
of  the  animal  body,  thus  touching  a  province  of  investiga- 
tion which  has  hitherto  been  far  too  little  cultivated.^'' 

Consideration  of  enzyme  action  does  not  come  within 
the  scope  of  these  studies,  but  it  appears  to  be  common 
to  both  animal  and  plant.  According  to  Vines  the  chief 
kinds  of  enzymes  which  have  been  found  in  plants  are  : — 

"  (1)  Those  which  act  on  carbohydrates,  converting 
the  more  complex  and  less  soluble  carbohydrates 
into  others  of  simpler  composition  and  greater 
solubility. 

"  (2)  Those  which  act  on  fats,  decomposing  them  into 
glycerine  and  fatty  acid. 

"  (3)  Those  that  act  on  glucosides,  glucose  being  a 
constant  product. 

"  (4)  Those  that  act  on  the  more  complex  and  less 
soluble  proteids,  converting  them  into  others 
which  are  more  soluble  and  probably  less  com- 
plex, or  decomposing  them  into  non-proteid 
nitrogenous  substances  (amides,  etc.)." 

As  regards  a  comparison  of  fats  in  animals  and  plants, 
Sachs  showed  as  long  ago  as  1858  that  in  the  germination 
of  seeds  containing  fat,  a  transference  of  the  fatty  oils  from 
the  cotyledons,  or  from  the  endosperm  into  the  growing 
parts  of  the  seedling,  appears  to  take  place,  and  this  was  con- 
firmed by  chemical  analysis  by  Peters.     In  his  twenty-first 


ANIMAL  AND   VEGETABLE  188 

leeture  Sachs  said ;  "  It  appears  that  the  fats  can  pass 
through  the  closed  tissue-cells  as  such  ;  though  of  course 
the  greater  part  of  them  is  transformed  into  starch  and 
sugar  for  transport  and  use.  Similar  phenomena  with 
respect  to  fats  occur  moreover  in  the  animal  body,  where 
the  fats  entering  into  the  stomach  are  in  the  first  place 
emulsified  by  the  secretion  from  the  pancreas,  that  is, 
they  become  converted  into  exceedingly  fine  drops  and 
then  saponified.  .  .  .  The  presence  of  fats  in  the  seedling 
can  only  be  explained  by  assuming  that  glycerine  and 
fatty  acids  travel  from  cell  to  cell,  and  are  continually 
becoming  reunited  for  the  formation  of  fat." 

In  the  case  of  plants  in  dry  climates,  or  so  situated  that, 
for  any  reason,  transpiration  from  their  outer  surfaces 
must  be  diminished,  they  are  characterised  by  the  greatly 
thickened  and  cuticularised  walls  of  their  epidermal  cells. 
Deposits  of  wax  are  also  present  in  the  cutinised  layers  of 
the  epidermis,  and  consequently  water  will  flow  off  from 
the  epidermis  without  wetting  it.  The  wax  is  sometimes 
spread  over  the  surface  of  the  cuticle  as  a  wax  covering. 
This  is  the  case  in  most  fruits,  where,  as  is  so  noticeable  in 
plums,  it  forms  the  so-called  bloom.     (Strasburger.) 

There  can,  I  think,  be  no  doubt  that  the  main  purpose 
underlying  the  provision  of  the  wax  covering  of  fruits  is 
the  preservation  of  their  absolute  insulation,  and  one  can 
be  sure,  even  without  examination,  that  where  the  outer 
skin  or  rind  of  a  fruit  is  of  comparatively  delicate  texture — 
as  of  the  plum — while  the  fruit  itself  is  juicy  and  highly 
conductive,  the  protective  "  bloom  "  will  be  found  to  be 
most  abundantly  provided. 

There  is  at  least  some  analogy  between  this  and  the 
sebaceous  secretion  of  the  human  epidermis  ;  both  are 
apparently  designed  for  the  performance  of  the  same 
function. 

In  cases  where  wax  is  absent  or  in  greatly  diminished 


134      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

quantity,  protection  of  a  similar  nature  is  afforded  by  resin, 
or  by  a  covering  or  capsule  of  a  fibrous  character,  as,  for 
instance,  in  the  leaf  of  the  ivy  and  the  capsules  of  various 
beans  and  seeds,  etc. 

In  regard  to  the  comparison  by  Sachs  of  the  laticiferous 
vessels  of  plants  to  blood-vessels  of  vertebrate  animals,  he 
instanced  the  fact  that  when  a  milky  stem  is  cut  not  only 
the  low  cut  surface  of  the  apical  portion  but  the  upper  one 
of  the  root-stock  also  extrudes  the  latex.  Besides,  the 
laticiferous  vessels  are  extremely  narrow  capillary  tubes, 
the  normal  terminations  of  which  in  the  buds,  leaves,  and 
root-apices  are  closed.  How,  he  asked,  could  fluid  flow 
out  at  all  on  cutting  such  capillaries  closed  at  the  ends 
unless  the  fluid  was  under  pressure  ?     "  When  we  wound 


Fig.  69. 

Cells   from   the   leaf  of  Elodea  ; 
p,  protoplasm. 


Fig.  70. 
Two  cells  from  a  staminal  hair 
of  Tradescantia. 


ourselves  the  blood  does  not  simply  flow  out,  it  is  driven 
out." 


ANIMAL   AND   VEGETABLE  135 

In  regard  to  the  movement  of  protoplasm  in  plants 
some  interesting  facts  are  given  by  Green.  In  cells  from 
the  leaves  of  Elodea  and  the  staininal  hairs  of  Tradescantia, 
to  take  two  examples,  the  cm*rent  appears  to  circulate, 
as  will  be  seen  from  the  two  figures  on  the  preceding  page. 

The  same  author  has  much  to  say  upon  the  subject  of 
rhythmic  movement  in  plants.  "  If  we  look  back,"  he 
writes,  "  to  the  behaviour  of  the  contractile  vacuole  of 
chlamydomonas,  we  are  struck  by  the  fact  that  its  pulsations 
occur  with  a  certain  definite  intermittence  so  long  as 
they  are  not  interfered  with  by  external  conditions.  The 
vacuole  dilates  slowly,  reaches  a  certain  size,  and  suddenly 
disappears  ;  then  is  gradually  formed  again,  and  the  series 
of  events  is  repeated.  This  regular  intermittence  con- 
stitutes what  is  often  spoken  of  as  rhythm.  The  rhythm 
which  is  so  easily  seen  in  the  case  of  pulsating  vacuoles  is 
characteristic  also  of  those  less  obvious  changes  in  proto- 
plasmic motility  which  lead  to  the  variations  of  turgidity 
in  different  organs,  particularly  in  those  which  are  growing. 
During  the  growth  in  length  of  a  symmetrical  organ,  such 
as  a  stem  or  root,  the  apex  points  successively  to  all  points 
of  the  compass.  This  is  the  result  of  a  rhythmic  variation 
of  the  turgidity  of  the  cells  of  the  cortex.  If  we  consider 
a  longitudinal  band  of  such  cells,  we  find  that  at  a  certain 
moment  the  ceils  are  at  their  point  of  maximum  turgidity, 
and  the  growing  apex  is  made  to  bend  over  in  a  direction 
diametrically  opposite  to  this  band.  The  turgidity  of  this 
band  then  gradually  declines  to  a  minimum,  and  again 
increases  slowly  to  a  maximum.  If  we  conceive  of  the 
circumference  of  the  organ  as  divided  into  a  number  of  such 
bands,  we  can  gain  an  idea  of  the  changes  in  turgidity 
which  cause  the  circumnatation.  Each  band  is  in  a 
particular  phase  of  its  rhythm  at  any  given  moment,  and 
the  successive  bands  follow  one  another  through  the  phases 
of  their  rhythm  in  orderly  sequence,  so  that  when  one  is  at 


136       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

its  maximum,  another  diametrically  opposite  to  it  is  at  its 
minimum.  The  phases  of  maximum  and  minimum  tur- 
gidity  thus  pass  rhythmically  round  the  organ,  and  the 
apex  is  consequently  compelled  to  describe  a  spiral  line  as 
it  grows.  .  .  .  It  is  not  infrequent  for  the  rhythmic  change 
in  the  turgescence  to  affect  only  two  sides  ...  its  changes 
will  thus  resemble  those  of  a  flattened  organ  which  can 
only  be  made  to  oscillate  backwards  and  forwards." 

Until  I  read  Green's  Vegetable  Physiology  I  was  not 
aware  that  this  rhythmicality  of  movement  had  been 
observed,  but  the  subject  is  to  me  one  of  peculiar  interest. 
It  so  happens  that  some  years  ago  I  carried  out  a  series  of 
galvanometric  tests  with  plants — ^invariably  at  night — 
and  took  note  of  phenomena  which,  in  their  electrical 
aspect,  were  suggestive  of  rhythmic  inspiration  and 
respiration. 

The  paralysis  or  destruction  of  protoplasmic  movement 
in  both  animal  and  vegetable  bodies  appears  to  occur  from 
identical  causes,  as  will  be  seen  on  reference  to  the  Study 
of  Amoeboid  Movement. 

One  question  which  has  engaged  my  attention  is : 
Can  there  be  any  analogy  between  the  propagation  of 
impulse  in  mammal  and  plant  ?  Though  the  possession  of 
nerves  is  denied  to  the  latter  by  some  authorities,  there  is 
little  if  any  doubt  that  they  are  present  in  a  rudimentary 
form,  and  in  such  case  the  propagation  of  stimuli  should, 
logically,  be  possible. 

Green  remarks  :  "In  considering  broadly  the  result 
of  stimulation  "  (of  plants)  "  we  must  notice  at  the  outset 
that  it  provokes  a  purposeful  response. '  The  living 
substance  appears  to  have  a  definite  aim." 

"  If  any  one  of  the  small  leaflets  of  a  leaf,  on  a  shoot  of 
Mimosa  with  five  or  six  leaves,  is  stimulated  by  means  of 
the  hot  focus  of  a  burning  glass,  all  the  other  leaflets  of  the 
same  leaf  gradually  fold  together,  and  after  a  time  the 


ANIMAL  AND   VEGETABLE  137 

large  motile  organ  at  the  base  of  the  main  petiole  also 
becomes  bent,  and  again  after  a  few  seconds  the  stimulation 
extends  to  the  nearest  neighbouring  leaf,  then  to  the 
succeeding  one,  and  so  on,  till  at  last  ail  the  leaves  of  the 
shoot  have  made  the  movement."     (Sachs.) 

The  rate  of  propagation  of  stimuli  in  the  plant,  as 
compared  with  man,  is,  of  course,  relativel\'  very  slow. 
That  is,  if  we  regard  it  as  a  pm'el}^  physical  process  in  the 
sense  that  when  a  stretched  string  is  jerked  at  one  point 
the  whole  string  vibrates.  But  if  we  take  the  rate  of 
conduction  of  a  feeble  electrical  stimulus,  I  do  not  think  it 
will  be  found  to  differ  materially.from  the  rate  of  conduction 
in  a  human  nerve. 


138      STUDIES   IN   ELECTRO-PHYSIOLOGY: 


Chapter    X 

AMCEBOID    MOVEMENT 

"  The  protoplasm  tends  during  life  to  exhibit  move- 
ments which  are  apparently  spontaneous,  and  when  the 
cell  is  uninclosed  by  a  membrane  a  change  in  the  shape,  or 
even  in  the  position  of  the  cell,  may  be  thereby  produced." 
(Schafer.) 

One  of  the  constituents  of  cell-protoplasm  is  called 
nucleo-protein,  and  the  normal  supply  of  iron  to  the  body  is 
contained  in  the  nucleo-proteins  of  plant  and  animal  cells. 

A  cell  possesses  the  power  of  breathing,  i.e.,  taking  in 
oxygen. 

"  There  is  no  doubt  that  protoplasmic  movement  is 
essentially  the  same  thing  in  both  animal  and  vegetable 
cells.  But  in  vegetable  cells  the  cell-wall  obliges  the 
movement  to  occur  in  the  interior."     (Halliburton,  1915.) 

What  is  the  nature  of  that  movement  ?  I  learn  from 
the  same  source  that  if  a  living  amoeba  is  v/atched  for  a 
minute  or  two,  an  irregular  projection  is  seen  to  be  gradu- 
ally thrust  out  from  the  main  body  and  retracted,  a  second 
mass  is  then  protruded  in  another  direction,  and  gradually 
the  whole  protoplasmic  substance  is,  as  it  were,  drawn  into 
it.  The  amoeba  thus  comes  to  occupy  a  new  position, 
and  when  this  is  repeated  several  times  we  have  locomotion 
in  a  definite  direction,  together  with  a  continual  change  of 
form.     (Halliburton,  1915.) 

Is  it  not  possible  to  explain  this  movement  by  the 
electrical  law  of  attraction  and  repulsion  ?     Iron,  as  I  have 


ANIMAL   AND   VEGETABLE  189 

remarked  elsewhere,  is  fifth  in  the  scale  of  electro-positives 
and  oxygen  at  the  bottom  of  the  list  of  electro-negatives  ; 
and  providing  that  osmosis  can  take  place  and  there  is  an 
exciting  solution,  such  electrical  action  may  very  well  occur. 

Upon  the  assumption  that  it  does  so  occur  let  us  see 
how  the  movements  of  the  amoeba  are  affected  by  stimuli. 

"  (1)  Changes  of  Temperature. — Moderate  heat 
acts  as  a  stimulant.  The  movement  stops  when  the 
temperature  is  lowered  near  the  freezing-point  or  raised 
above  45°  C. 

"  (2)  Chemical  Stimuli. — Distilled  water  first  stimu- 
lates, then  stops  amoeboid  movement.  In  some  cases 
protoplasm  can  be  almost  entirely  dried  up,  but  remains 
capable  of  renewing  its  movement  when  again  moistened. 
Dilute  salt  solution  and  very  dilute  alkalies  stimulate  the 
movements  temporarily.  Acids  or  strong  alkalies  per- 
manently stop  the  movements  ;  ether,  chloroform  .  .  . 
also  stop  it  for  a  time. 

"  Movement  is  suspended  in  an  atmosphere  of  hydrogen 
or  carbonic  acid,  and  resumed  on  the  admission  of  air  or 
oxygen ;  complete  withdrawal  of  oxygen  will  after  a 
time  kill  protoplasm. 

*'  (3)  Electrical. — Weak  currents  stimulate  the  move- 
ment, while  strong  currents  cause  the  cells  to  assume  a 
spherical  form  and  to  become  motionless." 

I  will  repeat,  but  paraphrase,  the  foregoing — 

(1)  Change  of  Temperature. — Moderate  heat  acts  as  a 
stimulant  by  lowering  internal  resistance.  The  movement 
stops  when  the  temperature  is  lowered  near  the  freezing 
point  because  of  the  enormous  increase  of  internal  resist- 
ance so  created,  and  as  protoplasm  dies  at  45°  C.  (or 
thereabouts),  that  temperature  would  naturally  bring 
about  cessation  of  movement  by  killing  the  protoplasm. 

(2)  Chemical  Stimuli. — ^Distilled  water,  regarded  as  a 
foreign  substance  or  fluid,  may  bring  about  a  momentary 


140       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

disturbance,  but  by  reason  of  its  high  resistance  would  tend 
to  stop  movement  after  a  short  time.  In  some  cases 
protoplasm  can  be  almost  entirely  dried  up,  but  remains 
capable  of  renewing  its  movement  when  again  moistened- 
Its  electrical  activity — and  especially  capacity — is  depen- 
dent upon  the  presence  of  conductive  moisture,  and  when 
not  so  moistened  it  would  become  inert.  That  dilute  salt 
solution  and  very  dilute  alkalies  stim^uiate  the  movements 
temporarily  by  lowering  internal  resistance  is  what  might 
reasonably  be  expected.  As,  however,  there  would  be 
some  alteration  of  the  chemical  composition  of  the  cell- 
contents  the  efficiency  of  the  cell  would  no  doubt  be  ulti- 
mateh'^  impaired.  Obviously  also  acids  or  strong  alkalies 
would  permxanently  stop  the  movemxcnts  by  causing 
diffusion  ;  ether  and  chloroform,  as  is  well  known,  interfere 
with  conduction,  and,  moreover,  I  am  quite  sure  that  the 
least  trace  of  tincture  of  nux  vomica  would  be  fatal.* 

That  movement  is  suspended  in  an  atmosphere  of 
hydrogen  or  carbonic  acid  calls  for  no  explanation,  but  the 
fact  that  complete  withdrawai  of  oxygen  will,  after  a  time, 
kill  protoplasm  is  a  strong  argum.ent  in  favour  of  the 
hypothesis  that  movement  is  due  to  electrical  action. 

(3)  Electrical. — Weak  currents,  by  supplementing  the 
natural  energy  of  the  cell,  stimulate  the  movement,  but 
strong  currents  paralyse  the  protoplasm,  or  by  disrupting 
its  electrical  structure  cause  it  to  revert  to  its  original 
shape  when  at  rest. 

In  considering  the  theoretical  solution  I  have  offered 
of  amoeboid  movement,  it  is  as  well  to  bear  in  mind  that 
although  the  chemical  composition  of  the  dead  amoeba  can 
be  resolved  by  analysis,  such  is  not  the  case  with  the  living 
amoeba,  in  which,  in  all  probability,  these  chemical  sub- 
stances are  represented  by  their  groups  of  ions.  If  that  is 
so  it  can  readily  be  imagined  that,  with  a  constant  intake  of 

*  See  experiment  Avith  begonia  (p.  159). 


ANIMAL  AND   VEGETABLE  141 

oxygen,  a  complex  electro-chemical  action  between  it  and 
the  iron  in  the  cell  may  be  set  up,  which  by  attraction  and 
repulsion  gives  rise  to  the  observed  phenomena. 

In  this  connection  reference  may  usefully  be  made  to 
the  experiments  of  Ampere.  He  proved  by  means  of 
movable  wires  that  attraction  was  shown  when  the  currents 
ran  in  the  same  direction  and  repulsion  when  in  opposite 
directions  ;  also  that  v,hen  two  finite  currents  are  inclined 
to  each  other  vs  ithout  crossing,  they  attract  when  both  run 
towards  or  both  run  away  from  the  comm.on  apex,  but 
repel  when  one  runs  towards  and  the  other  away  from  the 
apex. 

When  the  currents  are  in  the  same  direction,  the 
surfaces  oppositely  electrified  will  be  directly  opposed, 
and  therefore  attraction  ensues.  If  the  currents  are  in 
opposite  directions  the  surfaces  similarly  electrified  will 
oppose,  and  therefore  repel  each  other. 

In  protoplasm  there  are  many  possible  "  surfaces  "  in 
the  form  of  more  or  less  vertical  divisions  of  the  cell. 

Supposing  amoeboid  movement  to  be  due  to  either 
attraction  or  repulsion,  or  both,  causing  the  irregular 
projections,  we  can  understand  that  upon  one  current 
momentarily  ceasing 'to  flow  or  diminishing  in  intensity 
such  projection  would,  wholly  or  partially,  be  withdrawn, 
because  it  had  its  origin  in  the  first  instance  in  a  force,  and 
upon  that  force  being  no  longer  operative  or  altering  in 
intensity  a  change  of  form  would  take  place. 

It  will  be  remembered  that  early  in  the  last  century 
Davy  passed  a  current  tiirough  a  solution  of  potash,  and 
finding  that  the  potassium  went  to  one  of  the  poles  and  the 
oxygen  to  the  other,  concluded  that  the  two  elements  of  a 
compound  are  charged  with  different  electricities,  which 
are  neutralised  on  combination.  That  is  the  view  now 
held — -after  so  long,  and  so  lamentable  a  loss  of  time. 
"  The  actual  theory  of  ionisation  may  be  summed  up 


142      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

in  the  following  statement,  which  does  but  repeat  exactly 
the  ideas  of  Faraday  :  Bodies  are  composed  of  elements 
or  ions  charged,  some  with  positive,  others  with  negative 
electricity,  and  united  at  first  in  the  neutral  state.  Under 
the  influence  of  the  battery  current,  the  neutral  molecule 
dissociates  into  positive  and  negative  elements,  which  go  to 
the  poles  of  contrary  names.  The  decomposition  of  a 
neutral  salt  may  be  represented  by  such  an  equation  as  : 

NO,K  =/o.   +  K 

"  When  an  ion  leaves  a  solution  in  order  to  precipitate 
itself  at  an  electrode  charged  with  electricity  of  contrary 
sign — by  reason  of  the  attraction  exercised  between  two 
opposite  electric  charges — it  then  becomes  neutralised, 
which  means  that  it  receives  from  the  electrode  a  charge 
exactly  equal  but  of  contrary  sign  to  that  which  it  before 
possessed. 

"  Adopting  the  theoretical  ideas  put  forward  by 
Clausius,  Arrhenius  recognised  that  an  electric  current  was 
in  no  way  necessary  to  produce  the  dissociation  of  com- 
pounds into  ions.  In  dilute  solutions  the  bodies  dissolved 
must  be  separated  into  ions  by  the  mere  fact  of  solution. 
When  the  electrodes  of  a  battery  are  plunged  into  such 
solution,  the  ions  must  simply  be  attracted  by  them — 
the  positive  ions  by  the  negative  pole,  and  the  negative  ion 
by  the  positive  pole."     (Le  Bon.) 

According  to  Czapec,  in  any  solution  the  degree  of  this 
dissociation  depends  on  the  nature  of  the  salt,  the  tempera- 
ture of  the  solution  and  its  strength.  Acids  and  alkalies 
when  diluted  to  one  milligramme  in  one  litre  of  water  are 
entirely  broken  up  into  ions  and  cease  to  exist  as  acids  and 
salts.  Halliburton  tells  us  that  the  proportion  of  inorganic 
salts  in  the  blood  plasma  is  8-55  in  1,000,  or  approximately 
0*9  per  cent. ;  but  that  is  the  sum  total  of  all  the  salts. 


ANIMAL   AND   VEGETABLE  143 

I  do  not  know  what  the  percentage  of  alkali  in  the  cell-con- 
tents may  be.  In  any  case  there  must  be  a  certain  amount 
of  electrolysis  due  to  the  body  current  and  irrespective  of 
intra-cellular  action.  In  blood  plasma  sodium  is  present  to 
the  extent  of  about  0-334,  potassium  0-032,  and  chlorine 
0'364  per  cent. 

As  regards  rigor,  or  cessation  of  protoplasmic  move- 
ment in  plants,  Sachs  gives  the  following  information : — 

(1)  Temporary  cold-rigor  occurs  in  the  motile  organs 
of  Mimosa  pudica,  when  the  temperature  remains  for  some 
hours  below  15°  C.  The  lower  the  temperature  falls  below 
15°  C.  the  more  rapidly  the  rigor  sets  in. 

(2)  Temporary  heat-rigor  occurs  in  Mimosa,  in  moist 
air  at  40°  C.  within  one  hour  ;  in  air  at  45°  C.  within  thirty 
minutes  ;  in  air  at  49°-50°  C.  within  a  few  minutes.  The 
irritability  returns  after  a  few  hours  in  air  at  a  favourable 
temperature. 

Rigor  is  also  caused  by  the  withdrawal  of  oxygen  ; 
when  brought  into  the  air  the  plant  again  becomes  motile. 
Irritability  disappears  in  hydrogen  and  nitrogen  in  carbon 
dioxide  and  ammonia,  but  returns  on  free  exposure  to  air. 
Carbonic  oxide  gas  mixed  with  air  to  the  extent  of  twenty 
to  twenty-five  per  cent,  destroys  the  irritability. 

"  The  vapours  of  chloroform  and  ether  suspend  the 
irritability  of  the  motile  organs  (for  variations  of  light 
also),  without  destroying  the  life,  if  the  effect  does  not 
continue  too  long. 

"  Temporary  rigor  due  to  electric  influence  was  found 
by  Kabsch  to  occur  in  the  gynostemium  of  Stylidium.  A 
feeble  current  acted  as  a  stimulus  like  vibrations  ;  a 
stronger  one  caused  a  loss  of  irritability,  which  retiu'ned 
again,  however,  after  half  an  hour." 


144       STUDIES   IN   ELECTRO-PHYSIOLOGY: 


Chapter   XI 

THE   ELECTRO-PHYSIOLOGY   OF   THE 
MOTOR    APPARATUS 

Muscular  Tissue. 
The  two  chief  varieties  of  muscular  tissue  are — 

(1)  Unstriped  or  involuntary  muscle,  i.e.,  not   under 

the  control  of  the  will. 

(2)  Striped  or  voluntary. 

In  non-striated  muscular  tissue  the  cell  substance  is 
longitudinally  but  is  said  to  be  not  transversely  striated,  and 
each  cell  seems  to  have  a  delicate  sheath.  Between  the 
fibres  there  is  a  small  quantity  of  cementing  substance. 
Non-medullated  nerves  are  supplied  to  plain  muscular 
tissue  from  the  sympathetic  or  ganglionic  system,  and  this 
tissue  responds  but  slowly  to  a  stimulus  ;  the  contraction 
spreading  as  a  wave  from  fibre  to  fibre. 

As  it  may  help  us  to  a  clearer  understanding  of  the 
functioning  of  the  motor  apparatus  as  a  whole,  we  will  first 
consider  striated  tissue. 

Striated  Muscular  Tissue. 

Up  to  this  moment  I  had  not  seen,  in  any  work  upon 
Physiology,  any  illustration  of  the  structure  of  muscular 
tissue,  but  as  an  electrician  I  knew  what  I  should  find  when 
I  betook  myself  to  study.  I  should  find  sets  of  con- 
densers of  varying  capacity,  with  an  elastic  (compressible) 
substance   between   each  condenser,    and   with   absolute, 


ANIMAL   AND   VEGETABLE  145 

elastic,  sheath  insulation  ;  the  whole  being  so  arranged  as 
to  be  capable  of  neuro-electricai  contraction  in  almost 
every  direction.  The  chain  of  condensers  might,  indeed, 
contract  more  suddenly,  or  violently,  at  one  point  than  at 
another  point  or  points,  but  the  various  contractions  would 
be  designed  to  give,  under  impulse,  a  certain  definite 
movement  or  series  of  movements  to  the  muscle  under 
excitation. 

I  now  learn  from  Landois  and  Stirling's  Text-book 
of  Human  Physiology  that  each  muscular  fibre  receives 
a  nerve-fibre,  or  wire  from  a  central  station  or 
stations. 

The  elastic  sheath  is  called  sarcolemma,  and  has 
transverse  partitions  stretching  across  the  fibre  at  regular 
intervals.  Within  the  sarcolemma  is  the  contractile 
substance  of  the  muscle.  This,  sarcous,  substance  is 
marked  transversely  by  alternate  light  and  dim  layers, 
stripes,  or  discs. 

These  muscular  compartments  contain  the  sarcous 
substance,  and  in  each  compartment  there  is  a  broad  dim 
disc,  forming  the  contractile,  or  compressible,  part,  on  the 
upper  surface,  as  shown  in  the  illustration  (p.  147)  ;  then, 
lower  down,  a  narrower,  "  clear,"  homogeneous,  soft  or  fluid 
substance  ;  then  a  membrane  (called  Krause's  membrane), 
and  another  clear  substance,  followed  by  a  dim  (com- 
pressible) disc,  and  so  on  throughout  the  fibre. 

Let  us  imagine  the  sarcolemma  to  be  composed  of 
india-rubber,  at  all  events  on  its  inner  side,  the  dim 
substance  to  be  an  elastic  buffer,  the  "  clear  "  lines  to  be 
conducting  plates  or  discs,  and  Krause's  membranes  or 
Dobie's  lines  to  be  dielectric  in  character,  and  condenser 
action  is  suggested,  once  it  is  conceded  that  the  impulse  is 
neuro-electrical.  It  is  not  a  question,  as  I  have  argued  in 
another  cha^pter,  of  whether  the  impulse  is  neuro-electrical 
or  chemical,  but  of  which  action  is  precedent. 


146      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

It  will  be  useful  at  this  stage  to  bear  in  mind  certain 
electrical  laws — 

(1)  The  amount  of  electricity  induced  by  an  electrified 

body  on  surrounding  conductors  is  equal  and 
opposite  to  that  of  the  inducing  body. 

(2)  Induction  leads  to  discharge  as  well  as  charge. 

At  contact,  or  within  a  distance  bridgable  by  the 
tension,  the  charge  would  be  neutralised. 
(8)  Faraday  called  the  medium  through  which  induc- 
tion is  propagated,  such  as  air,  shellac,  paraffin 
wax,  etc.,  the  dielectric.  Air  is  taken  as  1  and 
all  other  substances  as  more  than  1.  Air,  there- 
fore, is  only  a  bad  conductor,  not  a  non- 
conductor. 

(4)  Faraday  further  supposed  the  particles  or  mole- 

cules of  the  dielectric  to  be  conductors  insulated 
from  each  other  ;  and  to  this  discovery  we  owe 
the  condenser,  and  the  Farad  as  the  unit  of 
capacity. 

(5)  Induction  propagates  itself  in  the  direction  where 

it  has  the  least  resistance  to  encounter. 

(6)  The    charge  that  a  body  receives  is   always  in 

proportion  to  the  facilities  it  offers  for  induction. 
If  a  body  is  so  situated  that  it  has  nothing  to  act 
on,  it  receives  no  charge,  or,  in  other  words,  has 
no  inductive  capacity. 

(7)  Discharge  begins  where  the  tension  is  greatest. 

(8)  The  greater  the  surface  over  which  electricity  is 

diffused  the  less  its  tension  at  any  particular 
point,  and  vice  versa. 

(9)  Electricity  is   exhibited   only   on  the  surface   of 

conductors. 

(10)  The  distribution  of  electricity  on  the  surface  of 
insulated  conductors  is  influenced  materially  by 
their  form. 

(11)  Electricity  concentrates  on  points  and  pro- 
jections. 


ANIMAL  AND   VEGETABLE  147 

The  sarcomeres,   or   divisions,    of   muscular   fibre   are 
shown  thus — 


biiiii 


TnTTTTTTTTnTTTTT 


and  such  a  fibre  consists  of  a  number  of  these  divisions,  of 
varying  diameter  and  area,  a  is  the  dim,  contractile 
part,  h  the  clear  substance,  and  c  Krause's  membrane  or 
Dobie's  line.  We  have  it  on  the  authority  of  Noel  Paton  that 
the  sarcolemma  is  "  a  delicate,  tough,  elastic  membrane, 
closely  investing  the  fibre,  and  attached  to  it  at  Dobie's 
lines." 

Sharpey's  drawings  of  a  portion  of  a  human  muscular 
fibre.  A,  and  of  separated  bundles  of  fibrils,  B,  are  shown 
on  the  next  page. 

The  motor  nerves  of  voluntary  muscle  are  efferent,  and 
therefore  the  impulse  is  from  the  brain,  downwards. 
Suppose,  then,  we  connect  these  sarcomeres  in  series  in  a 
battery  circuit,  thus  : — 


^arfh 


Earth     \ 


Fig.  71. 


The  law  of  electrical  attraction  would  at  once  come  into 
play.     The  upper  plate  would  induce  electricity  of  equal 


148       STUDIES   IN    ELECTRO-PHYSIOLOGY: 


•colemma. 

Fig.  72. 


-^r 


JSla5itc 


Fig.  73. 


Physiological  Explanation. — A  =  portion  of  a  human  muscular  fibre  ; 
B  =  separated  bundles  of  fibrils  :  a,  a,  larger  and  d,  c,  smaller  collections. 
In  A  the  letters  a,  b,  and  c  represent  the  dim  space,  the  clear  spaces, 
and  Krause's  membrane  respectively. 

Electrical  Explanation. — In  C  the  letters  a,  b,  and  c  denote  :  a,  a  com- 
partment filled  with  an  elastic  substance,  say,  viscous  india-rubber  solution  ; 
b,  metallic  or  other  conducting  plates  ;  and  c,waxed  paper  or  other  dielectric 
material. 


ANIMAL  AND   VEGETABLE 


149 


tension  but  of  opposite  sign  at  the  lower  plate,  and  that 
impulse  would  be  transmitted  throughout  the  series,  with 
the  result  that  contraction  would  take  place,  and  the  spaces 
a  be  compressed  and  bulge  at  the  sides,  while  the  sarco- 
lemma  would  also  be  contracted. 

The  effect  would,  in  fact,  be  like  the  compression  of  a 
concertina — 


L     I  1  1  1 1  1 

Fig.  7i. 
Concertina  expanded. 


Fig.  75. 
Concertina  compressed. 


except  that  the  projections  of  the  bellows  would  be  rounded 
instead  of  diagonal,  and  assume  the  appearance  of  the 
following  figure: — 


Fig.  76. 


But  this  would  only  give  us  a  straight  "  pull,"  and  as  a 
muscle  does  not  respond  to  impulse  in  that  way,  we  must 
see  how  Nature  overcomes  the  difliculty,  and  how  discharge 
or  neutralisation  is  brought  about. 

From  Fig.  72  (B)  we  see  that  the  fibrils  (and  it  must 


150      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

include  the  fibres)  are  of  varying  diameter,  and  we  have 
learned  that  (1)  tension  is  in  the  inverse  ratio  to  the  surface 
over  which  electricity  is  distributed,  (2)  electricity  concen- 
trates on  points  or  projections,  and  (3)  discharge  begins 
where  tension  is  greatest. 

If  we  were  making  an  artificial  muscular  fibre  we  could 
solve  the  problem  of  discharge  or  neutralisation  of  charge 
by  placing  studs  upon  our  conducting  plates,  as  in  Fig.  77, 

because  as  electricity  concen" 
trates  on  points  or  projections, 
and  discharge  begins  where  the 
tension  is  greatest,  the  plates 
^^^'  ^^'  would     discharge     when,     by 

attraction,  they  approached  each  other  sufficiently. 

We  could  also  vary  the  "  pull  "  both  as  regards  strength, 
or  velocity,  and  direction,  first  by  varying  the  area  of  some 
of  the  sarcomeres,  and  second  by  joining  them  up  in  groups 
in  series  or  series-parallel,  or  parallel. 

That  Nature  does  the  first  is  obvious  from  Fig.  72  (B). 
As  regards  the  second,  we  are  told  that  the  nerve-fibres 
of  voluntary  muscle  pierce  the  sarcolemma  and  terminate 
in  end-plates,  which  are  shown  to  connect  up  with  different 
groups  of  the  sarcomeres  of  muscular  fibre  in  the  following 
manner : — 


Fig.  78. 

Not  only  is  that  so,  but,  if  it  were  desired,  the  efferent 
impulse  could  be  converted  to  an  afferent  one  at  any  point 


ANIMAL   AND   VEGETABLE 


151 


by   the  simple  process   of  inserting   a   condenser   in  the 
nerve  circuit  : — 


mmTTn 


^"'"  Condenser 

Fig.  79. 

or,  as  it  appears  to  be  accomplished  in  the  human  body 


Fig.  80. 

both,  however,  are  on  exactly  the  same  principle. 

We  will  now  compare,  briefly,  Nature's  method  of 
discharge  or  neutralisation  of  charge  with  my  suggestion  of 
''  studs,"  and  discuss  the  whole  question  in  detail  later  on. 

As  given  by  Schafer  the  sarcomere  in  a  moderately 
extended  condition  is  shown  thus : — 


Jt 


M- 


M 


js 


^it 


Fig.|81. 


A;,  k  are  Krause's  membranes  or  Dobie's  lines,  H  the 
plane  of  Hensen,  and  SE  a  poriferous  sarcous  element. 


152       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

B  depicts  the  sarcomere  in  contracted  condition, 
compressed  and  elongated  and  bulging  at  the  sides. 

The    analogy    between 
■^-^  y^  metallic    plates   and   the 

ff.  /llH^GI^  I  f^  "  ^^^^^  "  spaces,  0,  of  the 
^BBgfliqy  j'^  sarcomere       cannot,      of 

M  course,     apply     to     the 

^^^'  ®^*  material    employed,    but 

only  to  its  electrical  character.  I  am  informed  that 
the  "  clear  "  spaces  are  largely  composed  of  potassium 
salts  in  fluid  or  semi-fluid  form,  and  that  the  dark 
vertical  lines  are  canals  or  pores,  open  towards  Krause's 
membrane,  but  closed  at  Hensen's  line.  The  clear 
spaces  are  therefore  conductive,  and  the  analogy,  electri- 
cally, holds  good.  In  the  contracted  muscle  the  clear 
part  of  the  muscle  substance  passes  into  the  canals  or 
pores  and  disajppears  from  view,  sv/elling  up  and  widening 
the  sarcous  element  and  shortening  the  sarcomere.  In  the 
extended  muscle,  on  the  other  hand,  the  clear  substance 
passes  out  from  the  canals  of  the  sarcous  element  and  lies 
between  it  and  the  membrane  of  Krause,  again  ready 
for  action. 

The  effect  of  the  completed  contraction  is  to  cause  the 
conducting  plates  to  approach  each  other  near  enough  to 
enable  them  to  discharge  or  neutralise  their  charge  by 
contact  through  some  invisible  pore  in  Hensen's  line  ;  or, 
possibly,  by  osmosis  or  diffusion. 

Alternatively  such  action  may  be  made  to  occur  by 
the  plates  being  withdrawn  to  a  sufficient  distance  to  cause 
induction  to  cease.  Then,  the  impulse  having  passed, 
they  would  be  restored  to  their  former  position,  in  readiness 
to  resume  the  performance  of  their  function. 

In  this  connection  we  may  recall  the  "  Muscle  telegraph  " 
of  Du  Bois-Reymond.  He  attached  a  piece  of  muscle  to 
a  movable  disc  and  placed  the  former  in  the  circuit  of  a 


ANIMAL   AND   VEGETABLE  153 

Leyden  jar.  When  connection  was  made  the  muscle 
contracted  and  the  disc  was  made  to  move.  With  two 
muscles  and  two  discs,  battery  power,  and  suitable  means 
for  the  rapid  neutralisation  of  charge,  an  electro-mechanical 
apparatus  to  exhibit  signals  in  the  Morse  Code  could  easily 
be  made. 

I  have  no  information  as  to  the  composition  of  Krause's 
membrane,  but  if  it  does  not  exist  and  is  not  a  bad  con- 
ductor of  neuro- electricity,  then  the  problem  of  muscular 
contraction  offers  the  most  extraordinary  series  of  coinci- 
dences I  ever  heard  of.  In  considering  this  point,  how- 
ever, it  must  be  remembered  that  a  good  conductor  of  high 
may  not  conduct  lo;v  tension  electricity  at  all. 

So  far,  in  speaking  of  the  clear  spaces,  I  have  used  the 
words  "  plates  "  and  "  discs,  "  but  am  by  no  means  sure 
that  I  am  correct  in  doing  so.  Schafer  gives  an  illustration 
in   which   the   arrangement   of  the   conducting    elements 


«  ^  y  ^  ^  II  <>  'I 

<l  (>     o  <i       II      |i      II       II 

(I  C  1    <i  < .- 

I'  I  >   •'  <l    <l    I 

II  II  II  II  II    11    II   I 


^ 


J? 


JC 


Fig.  83. — Portion  of  Leg-Muscle  of  Insect  treated  with  Dilute  Acid. 
S,  sarcolemma  ;    D,  dot-like  enlargement  of  sarcopiasm  ;    K,  Krause's 
membrane.     The    sareous   elements  are   dissolved    or   at  least   rendered 
invisible  by  the  acid.     {Sdiiifer.) 

appears    to   my    mind  to   be   more   consistent   with   the 
force  exerted  by  muscle  under  what  must  be  considered 


154       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

comparatively  feeble  stimulus.  Electricity  concentrates  on 
points  and  projections,  and  in  that  connection  the  figure 
assumes  a  more  than  usual  importance. 

We  may  now  study  the  physiology  of  muscular  fibre 
to  see  if  there  are  any  accepted  facts  or  views  which  are 
antagonistic  to  ours,  and  if  so,  whether  they  are  susceptible 
of  explanation  other  than  that  given  by  the  physiologist. 

"  A  nerve-fibre  usually  enters  a  muscle  at  the  point 
where  there  is  the  least  displacement  of  the  muscular 
substance  during  contraction." 

The  electrician  would,  of  course,  connect  his  line  or 
battery  wire  in  such  manner  as  to  avoid  interference  with 
the  movable  or  active  part  of  the  apparatus. 

The  next  paragraph,  from  Landois  and  Stirling,  will,  I 
fear,  bring  me  into  direct  conflict  with  some  accepted  views. 

"  Stimuli  are  simply  various  forms  of  energy,  and  they 
throw  the  muscle  into  a  state  of  excitement,  while  at  the 
moment  of  activity  the  chemical  energy  of  the  muscle  is 
transformed  into  work  and  heat,  so  that  the  stimuli  act  as 
discharging  forces  .  .  .  the  excitability  varies  as  the 
temperature  rises  or  falls." 

I  cannot  agree  with  the  view  that  stimuli  are  various 
forms  of  energj^  holding,  as  I  do,  that  they — the  natural 
stimuli^ — are  manifestations  of  neuro-electrical  energy  ; 
although  certain  chemical  changes  are  undoubtedly  con- 
sequent upon  them. 

Again,  it  is  not  altogether  correct  to  say  that  stimuli 
act  as  discharging  forces.  They  act  first  as  charging 
forces,  and  when  contraction  has  taken  place — and  not 
before — cause,  as  a  result  of  that  contraction,  discharge 
or  neutralisation  of  charge. 

In  regard  to  the  effect  of  temperature  upon  the  ex- 
citability of  muscular  fibre  the  explanation  can,  I  venture 
to  think,  be  given  in  three  words,  i.e.,  "  Heat  assists 
conduction." 


ANIMAL  AND   VEGETABLE  155 

With  a  rise  of  temperature  the  resistance  of  the  clear 
substance  of  the  muscle  and  of  Krause's  membranes  would 
be  reduced  ;  with  a  fall  of  temperature  the  resistance  of 
both  would  be  increased.  What  the  relative  fall  or  rise  of 
resistance  is  I  have  no  means  of  determining,  but,  broadly 
speaking,  a  considerable  rise  of  temperature  might  seriously 
impair  the  action  of  the  condenser-compartments  (sar- 
comeres) by  breaking  down  the  resistance  of  Krause's 
membranes,  and  so,  wholly  or  partly,  short-circuiting  the 
condensers ;  while  a  considerable  fall  of  temperature 
might  increase  the  resistance  of  the  clear  substance  to  such 
an  extent  that  the  low-tension  nerve-charge  could  not 
overcome  it,  with  the  result  that  the  muscle  would, 
temporarily,  become  paralysed. 

A  further  section  deals  with  excised  muscles,  and  lays 
stress  upon  the  fact  that  a  series  of  stimuli  of  the  same 
strength  causes  a  series  of  contractions  which  are  greater 
than  at  first  (Wundt),  and  argues  from  that,  that  although 
the  first  feeble  stimulus  may  be  unable  to  discharge  a 
contraction  (?  cause  a  contraction)  the  second  may,  because 
the  first  one  has  increased  the  muscular  excitability  (Fick). 

By  excised  muscles  I  understand  dead  muscles.  There 
is  an  essential  difference  between  the  living  and  the  non- 
living ;  but  even  in  non-living  muscular  fibre  we  should 
have  condenser-action  while  its  structure  remained  un- 
impaired. But  it  does  not  follow  that  the  conductivity  of 
the  clear  substance  and  the  resistance  of  Krause's  mem- 
branes would  be  exactly  the  same  as  in  living  muscle^ 
Discharge  cannot  occur  until  contraction  is  completed, 
and  whereas  in  living  muscle  one  impulse  may  be  sufficient, 
a  dozen  or  more  might,  conceivably,  be  conveyed  to  dead 
muscle  before  contraction  could  be  completed  and  dis- 
charge or  neutralisation  effected — if  its  capacity  is  altered 
by  death,  or  some  change  is  brought  about  by  death  in  the 
elasticity  of  the  sarcous  substance. 


156       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

Reading  on,  we  are  told  that  "  if  the  muscles  of  a  frog 
(Du  Bois-Reymond)  or  tortoise  (Briicke)  be  kept  in  a  cool 
place,  they  may  remain  excitable  for  ten  days,  while  the 
muscles  of  warm-blooded  animals  cease  to  be  excitable 
after  one  and  a  half  to  two  and  a  half  hours.  ...  A 
muscle  when  stimulated  directly,  always  remains  excitable 
for  a  longer  time  when  its  motor  nerve  is  already  dead." 

I  have  tested  toads  and  tortoises  galvanometrically  in 
years  gone  by,  and  have  been  astonished  at  their  super- 
abundant nerve  energy  as  compared  with  that  of  man. 
Moreover,  their  insulation,  absolute  and  internal,  is  such 
that  they  can  withstand  extremes  of  temperature  and  exist 
without  food  for  incredible  periods  of  time.  To  compare 
the  muscle  of  a- tortoise  with  that  of  a  warm-blooded  animal 
is  to  compare  an  ivy  leaf  with  a  deciduous  leaf.  By 
reason  of  its  higher  insulation  the  former  will  live  {i.e., 
remain  excitable)  for  months,  whereas  a  horse-chestnut 
leaf  will  perish,  under  the  same  conditions,  in  a  few  days. 
It  is,  to  my  mind,  purely  a  question  of  insulation.  Suppos- 
ing there  to  be  any  resistance  remaining  in  Krause's 
membranes  and  any  conductivity  in  the  clear  substance, 
condenser-action  would  continue — in  some  degree  ;  but  in 
the  dead  muscular  fibres  of  warm-blooded  animals  there 
would,  I  should  think,  be  rapid  diffusion,  short-circuit,  and 
consequent  cessation  of  condenser-action. 

The  statement  that  "  a  muscle  when  stimulated  directly 
always  remains  excitable  for  a  longer  time  when  its  motor 
nerve  is  already  dead  "  is  almost  elementary.  Part  of  the 
sensory  nerve  of  an  apple  is  its  stalk.  When  the  apple  is 
ripe,  and  it  falls,  Nature  seals  the  end  of  the  stalk  with  a 
resinous  insulating  substance.  Granting,  then,  the  sar- 
comeres to  be  structurally  intact,  a  dead  motor  nerve 
would  be  equivalent  to  the  sealed  sensory  nerve-ending  of 
the  apple.  On  the  other  hand,  if  the  motor  nerve  of  the 
muscle  was   maintained  in  a  moist  condition  it  would  not 


ANIMAL   AND   VEGETABLE  15T 

remain  excitable  for  so  long  a  time   nor  could  the  apple 
continue  to  resist  decay  if  its  stalk  was  unsealed  and  wet. 

Under  the  heading  "  Independent  Muscular  Activity,"  I 
am  told  that  "'  there  are  many  considerations  which 
show  that  excitability  is  independent  of  the  nervous 
system,  although  in  the  higher  animals  nerves  are  the  usual 
medium  through  which  the  excitability  is  brought  into 
action.  Thus  plants  are  excitable,  and  they  contain  no 
nerves.'^  The  italics  are  my  own,  and  emphasise  a  state- 
ment upon  which  the  whole  argument  depends.  That 
statement  also  furnishes  another  illustration  of  the  manner 
in  \vhich  the  student  may  be  side-tracked  from  the  main 
line  of  independent  thought  and  research.  He  is  told  by 
a  great  authority  that  plants  have  no  nerves,  and,  accepting 
the  dictum  with  the  respect  invariably  accorded  to  the 
teacher,  is  induced  to  follov/  a  false  line  of  reasoning. 

Every  plant  that  grows  in  the  soil  has  a  nervous 
organisation.  The  earth  is  the  negative  terminal  of 
Nature's  electrical  system,  as  the  air,  in  normal  conditions 
of  weather,  is  the  positive  terminal  ;  and  every  tree, 
plant,  or  vegetable  is  charged  by  the  earth,  through 
sensory  nerves,  or  closed  circuits,  extending  from  the  roots 
through  the  stem  and  stalks  and  thence  to  the  veins 
(nerve-fibres  or  fibrillse)  of  the  leaves.  These  all  yield  a 
negative  galvanometric  reaction,  while  those  parts  of  the 
leaves  between  the  veins,  as  v/ell  as  the  flower  end  of  all 
vegetables  and  fruits,  are  of  positive  sign.  Not  only  have 
plants  nerves,  but  I  shall  be  very  much  surprised  if  they 
are  not  found  to  possess  a  louver  form  of  motor  apparatus 
as  well. 

I  am  far  from  being  alone  in  this  opinion.  Ains worth 
Davis  says — 

"  It  has  been  shown  that  the  protoplasm  in  adjacent 
cells  may  be  permanently  united  by  fine  threads  of  the 
same  material  passing  through  the  cell -walls.     For  effecting 


158       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

movements  such  an  arrangement  is  invaluable,  and  this 
kind  of  continuity  seems  to  foreshadow  the  muscular 
fibres  of  animals.  .  .  .  The  '  continuity  of  protoplasm  ' 
has  here  also  an  important  bearing,  and  the  nerves  of 
animals  seem  prefigured."  It  is  known  that  plants  suffer 
from  chlorosis,  and  that  it  may  be  cured  by  putting  a  little 
soluble  iron  in  the  soil. 

Also  Sachs  says  in  his  Physiology  of  Plants  :  "  It  can 
scarcely  be  wondered  at  if  the  conclusion  is  drawn  that 
something  in  the  nature  of  nerves  exists  in  the  leaves  of 
DioTKBa,  as  appears  moreover  to  accord  with  the  in- 
sectivorous propensities  of  these  plants.  ...  In  any  case 
we  have  no  necessity  to  refer  to  the  physiology  of  nerves 
in  order  to  obtain  greater  clearness  as  to  the  phenomena  of 
irritability  of  plants  ;  it  will,  perhaps,  on  the  contrary, 
eventually  result  that  we  shall  obtain  from  the  process  of 
irritability  in  plants  data  for  the  explanation  of  the 
physiology  of  the  nerves." 

In  the  vegetable  world  the  various  forms  of  life  have 
their  roots  in  the  negative  soil,  and  embryologists  have 
demonstrated  that  their  starch-sugars  are  of  Isevo-  and 
their  albumins  of  dextro-rotation.  Man  has  his  roots, 
so  to  speak,  in  the  positive  air,  and  the  rotation  of  his 
sugar-glycogen  and  albumins  is  directly  opposite  to  that 
of  the  plant.  That  line  of  thought  is  worth  following,  and 
may  be  productive  of  valuable  results. 

A  good  deal  has  been  written  upon  the  effect  of  curara 
upon  motor  nerves.  My  own  research  has  shown  that 
certain  poisons  increase  the  resistance  of  the  nerve  sub- 
stance to  such  an  extent  that  the  nerves  are  unable  to 
transmit  impulse  ;  with  the  result  that  there  is  pain  so 
closely  resembling  that  attendant  upon  neuritis  and  sciatica 
as  to  introduce  error  into  diagnosis.  Moreover,  Professor 
Chunder  Bose  and  I  have  both  found  that  plants  are 
similarly  affected.     In   a   recent    experiment   I   tested   a 


ANIMAL   AND   VEGETABLE  159 

healthy  begonia  and  obtained  a  steady  deflection  of 
135  mm.  upon  the  galvanometer  scale.  The  injection  of 
two  minims  of  tincture  of  nux  vomica  into  the  stem 
reduced  that  deflection  to  zero  in  one  hour.  In  six  hours 
the  stem  fell,  the  leaves  separated  at  the  junction  of  stalk 
with  stem,  and  in  a  week  the  plant  was  rotten. 

The  point  laboured  by  at  least  some  investigators  seems 
to  be  that  although  a  nerve  or  nerves  may  be  paralysed  or 
deprived  of  conductivity  by  certain  poisons,  the  excitability 
of  muscle  may  not  be  so  affected,  and  therefore  the  muscle 
is  independent  of  nerve. 

Expose  that  theory  to  the  cold  light  of  reason.  In  the 
first  place,  the  poison — the  destructive  agent — must  pene- 
trate not  only  the  nerve  but  invade  the  whole  of  the  sarco- 
meres— as  is  possibly  the  case  in  gas  gangrene — if  the  latter 
are  to  be  equally  affected  ;  secondly,  if  the  resistance  of  the 
clear  lines  of  muscular  fibre  is  correspondingly  increased, 
so,  conceivably,  would  be  the  resistance  of  Krause's  mem- 
branes, and  therefore  contraction  might  still  be  possible, 
though  in  diminished  degree.  If  it  is  a  matter,  merely,  of 
poisoning,  or,  in  other  words,  "  sealing,  "  the  motor  nerve, 
the  excitability  should,  according  to  the  theory  I  have 
advanced,  endure  for  a  longer  period  than  if  the  nerve  had 
not  been  poisoned  or  insulated. 

Under  the  microscope  single  muscular  fibrillae  exhibit 
the  same  phenomena  as  an  entire  muscle,  in  that  they 
contract  and  become  thicker.  Though  there  is  difficulty 
in  observing  the  changes  that  occur  in  the  individual 
parts  of  a  muscular  fibre  during  the  act  of  contraction,  it 
appears  to  be  certain  that  the  muscular  elements  become 
shorter  and  broader  during  contraction  ;  that  is  to  say,  the 
transverse  striae  approach  nearer  to  each  other  in  the 
manner  I  have  indicated. 

Too  much  importance  should  not,  for  reasons  I  have 
given,  be  attached  to  experiments  with  dead  muscle  unless 


itij       STVniKS   IN    ELECTRO-PHYSIOLOGY: 

],c   personai    equation   has  been   allowed  for,   but  when 

!J! rents  of  high   tension  are  employed  this  may  be  dis- 

egarded  and  the  data  viewed  from  a  different  standpoint. 

For  example,  an  illustration  of  the  muscle-curve  produced 

by  the  applicat'on  of  a  single  induction-shock  to  a  muscle. 

as  given  in  Landois  and  Stirling,  is  full  of  interest,  although 

it  does  not  seem  to  have  conveyed  its  lesson. 

Let  us  see  if  we  can  i  earn  anything  from  it. 


Fig.  84. 

af,  abscissa  ;  ac,  ordinate  ;  ab,  period  of  latent  •  stimulation  ;  bd, 
period  of  increasing  energy  ;  de,  period  of  decreasing  energy  ;  ef,  elastic 
after-vibrations. 


Such  is  the  brief  explanation  of  the  curve,  but  it  is, 
needless  to  say,  elaborated  in  the  text.  Any  electrician 
acquainted  with  submarine  cable  telegraphy  would, 
however,  have  in  mind  what  is  terined  inductive  embarrass- 
ment, and  point  out  the  weii-known  fact  that  each  signal 
at  a  receiving  station  (and  muscle  is  a  receiving  station) 
takes  a  longer  time  to  leave  the  line  than  it  did  to  enter  it. 
A  momentary  signal  at  starting,  it  becomes  a  prolonged 
signal  at  its  destination,  and,  furthermore,  while  a  con- 
denser may  be  partially  discharged,  as  shown  by  the  curve 
de,  almost  instantaneously,  it  would  continue  to  discharge 
along  the  curve  ef.  All  this,  I  contend,  goes  to  show  that 
the  nerve  impulse  is  neuro-electrical,  and  that  muscular 
contraction  occurs  through  the  influence  of  induction  upon 
condenser-bodies. 


ANIMAL   AND    VEGETABLE  161 

At  the  risk  of  labouring  the  fact,  I  must  repeat  that  the 
tension  at  any  point  is  in  the  inverse  ratio  to  the  surface- 
area  over  which  electricity  is  distributed.  That  being  so 
it  follows,  logically,  that  the  tension  at  any  point  or  points 
may  be  varied  by  varying  the  surface-area  of  the  conducting 
plates,  discs,  or  membranes. 

Sarcolemma  and  Neurilemma. — I  have  classed  these 
together  because,  whatever  differences  may  exist  between 
them,  they  have  two  properties  in  common,  i.e.,  they  are 
both  elastic  and  both  either  dielectric  in  character,  or  they 
carry  a  dielectric  substance  or  substances  upon  or  in  them. 
If  sarcolemma  is  not,  in  itself,  of  comparatively  high 
resistance  it  must  carry,  on  its  inner  side,  a  resistant 
substance  or  material,  because,  if  it  were  not  so  carried, 
contact  might  occur  between  the  conducting  plates  or  discs 
or  points  of  the  sarcomeres.  Also  I  must  assume  that  the 
sarcolemma  is  very  elastic,  and  for  this  reason.  Suppose 
the  sarcolemma  not  to  exist,  and  that  in  its  place  was  a 
layer  of  dry  (highly  resistant)  air.  When  an  impulse  was 
sent  along  a  motor  nerve  to  cause  contraction  there  would 
be  nothing  to  impede  contraction,  and  the  maximum 
contractile  effect  would  be  obtained.  Betv.een  this 
unimpeded  movement  and  movement  governed  by  an 
elastic  material  there  would  be  a  wide  margin  of  difference 
— dependent  upon  the  compressibility  of  the  material — 
and  Nature  would  adjust  the  degree  of  elasticity  or  com- 
pressibility to  meet  requirements. 

Other  Insulating  Processes. 

Halliburton  gives  an  illustration  of  a  transverse  section 
of  the  sciatic  nerve  of  a  cat  which  will  repay  study. 

At  first  sight  one  is  forcibly  reminded  of  a  number  of 
bundles  of  insulated  wires  laid  in  bitumen  in  a  trough, 
and  we  shall,  I  think,  be  led  to  the  conclusion  that  that  view 

M 


162       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

is  not  without  foundation  when  we  examine  the  figure  in 

detail. 

Let  us  first  unravel  a  piece  of  ordinary  electric-light 
"  flex."     In  the  centre  are  a  number  of  fine  copper  wires 


/^i'rineuriuin 


2^erincunii 


Lu'nph  space 
Bpineuj'ium 


Fig.  85. 


which  we  will  call  fibrillae.  The  first  insulating  layer  is 
composed  of  red  cotton,  and  this  we  will  imagine  to  be  the 
endoneurium.  The  next  outer  layer  is  of  white  cotton 
(lymph  space),  while  the  outer  layer  or  perineurium  is  of 
green  silk — a  very  highly-resistant  material. 

In  the  illustration  given  above  it  will  be  seen  that  each 
bundle  of  nerve-fibres  is  encircled  by  a  lymph  space  lying 
between  two  insulating  processes  (endoneurium  and 
perineurium),  and  as  lymph  is  alkaline  and  therefore 
conductive,  another  problem  is  presented  for  solution. 

What,  in  this  particular  instance,  is  the  function  of 
lymph  ? 

Suppose  the  nerve-fibres  to  be  insulated  wires  connected  ■ 
in  a  special  circuit  for  a  special  purpose,  and  further  imagine 
these  wires  to  run  more  or  less  parallel  with  hundreds  or 
thousands  of  other  wires  in  different  branch  circuits,  each 
or  all  of  which  would  be  conveying  currents  or  transmitting 
impulses  in  the  same  or  opposite  directions.  The  result 
would  be  inductive  interference  with  the  fibres  of  the  sciatic 
nerve,  and  the  impulses  transmitted  by  them  would  be 
liable  to  continued  interruption. 


ANIMAL  AND   VEGETABLE 


168 


A  practical  remedy,  if  we  were  dealing  with  bundles  of 
insulated  wires,  would  be  to  copper-tape  each  bundle  or 
put  it  in  a  metal  tube,  so  that  induced  currents  could  be 
intercepted  by  the  tape  and  tube  and  prevented  from 
reaching  the  actual  conductors,  the  wires  or  nerve-fibres. 
That  appears  to  be  the  most  reasonable  view  to  take  of  the 
function  of  lymph  in  this  case.  It  is  hardly  possible  to 
regard  it  as  an  insulating  substance,  despite  its  tendency  to 
clot  and  form  a  "  colourless  coagulum  of  fibrin,"  in  view 
of  the  more  probable  explanation  I  have  suggested. 

Again  referring  to  the  figure  and  adhering  to  our  simile 
of  bundles  of  insulated  wires,  it  will  be  evident  that  if  we 
arrange  these  in  a  trough  and  pour  melted  bitumen  around 
them  the  bitumen  would  form  an  enveloping  sheath, 
corresponding,  roughly,  to  the  epineurium. 

We  will  take,  as  another  example,  the  core  of  a  sub- 
marine cable.  The  conductors — of  which  there  are  usually 
eight  or  more — are  separated  from  each  other  by  gutta- 
percha, and  the  total  insulation  is  made  up  of  three  layers 
of  gutta-percha  and  three  layers  of  Chatterton's  compound, 
superimposed  one  upon  the  other. 

As  an  instance  of  what  is  done  in  practice  I  will 
quote  from  Herbert's  Telegraphy. 

In  the  telegraph  system  of  the 
post-office  there  are,  of  course,  a  large 
number  of  telegraph  and  telephone 
circuits,  which  by  reason  of  their  being 
in  juxtaposition  require  about  the 
same  measure  of  protection  from 
induction  as  the  multifarious  fibrillee 
of  the  sciatic  nerve. 

In  order  to  get  rid  of  inductive  interference  various 
devices,  such  as  twisting  the  wires,  were  tried  with  more 
or  less  success,  but  the  method  which  has  given  the  best 
results  is  thus  described  by  Mr.  Herbert :   "  The  conductor 


Fig.  86.— Section  of 
A  Screened  Cable. 


164      STUDIES   IN   ELECTRO-PHYSIOLOGlT  : 

is  first  covered  with  three  wrappings  of  paper,  the 
first  of  which  may  be  either  spiral  or  longitudinal,  but  the 
other  two  are  invariably  applied  spirally.  The  spiral 
wrappings  are  applied  so  as  to  form  a  helical  air-space 
throughout  the  length  of  the  core.  The  conductor  thus 
insulated  is  then  enclosed  in  a  final  wrapping  of  paper, 
forming  a  closed  helix  without  overlap.  Over  this  is  laid 
a  helical  winding  of  copper  tape,  with  an  overlap.  .  .  .  The 
whole  of  the  cores  are  laid  together,  and  a  seamless  cylin- 
drical sheathing  of  lead,  at  a  temperature  of  600°  F.,  is 
applied  to  the  cable." 

This  description  refers,  needless  to  say,  to  a  land  cable, 
and  the  paper  and  air  insulation  are  designed  to  reduce  the 
capacity. 

"  The  copper  tape  forms  a  continuous  conducting  tube 
around  the  wire,  and  as  this  tube  is  earth-connected,  either 
by  direct  contact  with  the  lead  sheathing  or  indirectly  by 
the  tapes  of  the  other  cores,  it  will  be  obvious  that  induction 
between  the  wires  cannot  occur.  Firstly,  Faraday's 
experiments  showed  that  variations  in  the  differences  of 
potential  existing  or  produced  between  conductors  within 
a  metallic  covering  produce  no  effect  outside  that  covering. 
Secondly,  any  source  of  inductive  disturbances  brought  to 
bear  upon  a  screened  conductor  produces  the  whole  of  its 
effects  upon  the  copper  tape.  The  magnetic  lines  of  force 
induce  currents  along  the  tape  covering  the  wire,  and  as  this 
path  is  highly  conductive,  practically  the  whole  of  the 
energy  is  absorbed  by  it.  In  order  to  produce  an  inductive 
effect,  currents  must  be  generated  in  the  tape  of  the 
disturbing  wire  and  also  in  the  tape  of  the  disturbed  wire 
before  the  second  conductor  is  reached." 

It  is  at  least  a  coincidence  that  in  the  "  flex,"  the  cable 
and  the  nerve,  the  axis  cylinder  should  be  composed  of  a 
bundle  of  funiculi  instead  of  one  wire,  and  that  the  insula- 
tion should  take  the  form  of  several  layers  of  a  semi-plastic 


ANIMAL   AND   VEGETABLE  165 

material.  One  might,  indeed,  be  tempted  to  think  that 
while  the  physiologist  has  held  the  electrician  more  or  less 
in  contempt,  the  latter  has  achieved  his  object  by  copying 
certain  of  the  natural  processes  described  by  the  former. 
That  this  is  so  is,  however,  open  to  doubt,  because  it  is 
questionable  whether  at  the  inception  of  telegraphy  there 
was  in  existence  any  illustration  published  of  the  nervous 
system  of  man  which  could  have  so  guided  or  inspired  the 
electrician.  Moreover,  it  is  difficult  to  believe  that  were 
these  systems  of  insulation  borrowed  from  or  suggested  by 
any  physiological  work  we  should  have  remained  in 
ignorance  of  the  true  functioning  of  the  nervous  system  for 
so  long  a  period  of  time.  The  explanation,  no  doubt,  is 
that  the  electrician  discovered  certain  natural  laws  and, 
applying  them,  unconsciously  imitated  the  work  of  the 
Creator. 

Termination  of  Nerves  in  Muscle. 

In  the  voluntary  muscles  the  motor  nerve-fibres  have 
special  end-organs  called  end-plates.  In  the  involuntary 
muscles  the  fibres  form  complicated  plexuses  near  their 
termination.  .  .  .  Considerable  variation  in  the  shape  of 
the  end-plates  occurs  in  different  parts  of  the  animal 
kingdom.  In  the  voluntary  muscles  the  fibre  branches 
two  or  three  times,  and  each  branch  goes  to  a  muscular 


Fig.  87.  (After  Schafer.) 

fibre.  Here  the  neurilemma  becomes  continuous  with  the 
sarcolemma,  the  medullary  sheath  stops  short,  and  the 
axis  cylinder  branches  several  times. 


166       STUDIES   IN  ELECTRO -PHYSIOLOGY  : 

A  termination  of  meduilated  nerve-fibres  in  tendon 
near  the  muscular  insertion  is  shown  by  Golgi  (Fig.  87), 
but  more  interesting  is  Szymonowicz's  drawing  of  end- 
plates  with  the  axis  cylinders  and  their  final  ramifications 
of  fibrillge,  as  it  also  makes  it  clear  that  the  muscular  fibres 
vary  in  diameter  and  therefore  in  tension  also. 

The  word  "  plates  "  is  confusing.  They  do  not  look 
like  plates,  but  more  closely  resemble  bunches  of  wire* 
The  term  "  end-organs  "  is  in  keeping  with  their  appearance 
and  probable  function,  and  we  will  so  refer  to  them. 

We  must  ndt  for  one  moment  depart  from  our  hypo- 
thesis of  the  condenser-compartment  action  of  muscular 
fibre,  nor  forget  that  the  contraction  of  muscle  is  not  along 
a  straight  line  but  in  curves,  and,  furthermore,  that  the 
sarcomeres  of  a  muscular  fibre  may  not  be  required  to  be, 
and  obviously  are  not,  connected  wholly  in  series. 

Suppose  these  end-organs  to  be  composed  of  fibrillse, 
stretching  to  and  connecting  with  different  sets  of  sar- 
comeres, in  such  manner  that  those,  and  those  alone,  would 
be  directly  stimulated  or  acted  upon,  and  we  may  begin  to 
comprehend  in  some  measure  their  function  and  dis- 
tribution. 

Professor  Rosenthal  gives  the  following  account  of 
the  termination  of  nerve  in  muscle  :  "  The  nerve  passes 
into  direct  contact  with  the  muscle- substance.  .  .  .  The 
nerve-fibres,  in  their  course  within  the  muscle,  touch 
externally  many  muscle-fibres,  over  which  they  pass  before 
they  finally  end  at  another  muscle-fibre  .  .  .  only  those 
pulsate  at  which  the  nerve-fibre  ends.  .  .  .  The  nerve- 
sheath  is,  as  we  already  know,  a  real  isolator  as  regards  the 
process  of  excitement  within  the  fibre  ;  for  an  excitement 
within  a  nerve-fibre  remains  isolated  in  this,  and  is  not 
transferred  to  any  neighbouring  fibre.  It  is  quite  im- 
possible, therefore,  that  it  can  transfer  itself  to  the 
muscle-substance,   since  it  is   separated  from  the  latter 


ANIMAL  AND   VEGETABLE 


167 


not  only  by  the  nerve-sheath,  but  also  by  the  sarco- 
lemma. 

But  if  the  nerve-fibre  penetrates  the  sarcolemma,  and 
if  nerve-substance  and  muscle-substance  are  in  immediate 
contact,  then  the  transference  of  the  excitement  present  in 
the  nerve  to  the  muscle-substance  is  intelligible." 

The  plexuses  of  the  involuntary  muscles  probably  form 
part  of  a  closed-circuit  system  designed  to  maintain 
equilibrium.  The  plexus  of  Auerbach,  as  shown  in 
Halliburton,  is,  roughly,  thus : — 


Fig.  88. — ^Plexus  of  Auerbach. 


(A^ter  Capiat.) 


Without  unduly  taxing  the  imagination  one  could 
conceive  that  plexus  to  be  a  distributing  and  equalising 
station,  provided  in  each  of  its  branches  and  throughout 
its  ramifications  with  condensers  of  adjusted  capacity,  so 
that  at  each  and  every  point  there  would  be,  in  normal 
health,  a  certain  given  and  definite  tension.  By  "  equalis- 
ing "  I  mean  an  automatic  "  give-and-take  "  arrange- 
ment to  neutralise  any  excess  or  compensate  for  any 
deficiency. 


168      STUDIES   IN   ELECTRO-PHYSIOLOGY: 
DENDRONS   AND    SYNAPSES 

AND    THEIR   PrOBABLE    FUNCTION 

The  grey  matter  of  the  cerebellum  contains  a  large 
number  of  small  nerve-cells,  and  one  layer  of  large  cells. 
These  are  flask-shaped  and  are  called  the  cells  of  Purkinje. 
The  neck  of  the  flask  breaks  up  into  branches,  and  the  axis 
cylinder  process  comes  off  from  the  base  of  the  flask. 

The  whole  nervous  system  consists  of  nerve-cells  and 
their  branches,  supported  by  neuroglia  (epiblastic  or 
insulating  material)  in  the  central  nervous  system,  and 
by  connective  tissue  (binding  and  more  or  less  non- 
conductive)  in  the  nerves.  Some  of  the  processes  of  a 
nerve-cell  break  up  almost  immediately  into  smaller 
branches,  ending  in  arborescences  of  fine  twigs ;  these 
branches  are  now  called  dendrons.  One  branch  becomes  the 
long  axis  cylinder  of  a  nerve-fibre,  but  it  also  ultimately 
terminates  in  an  arborisation  ;  it  is  called  the  axis  cylinder 
process^  or,  more  briefly,  the  axon.  The  term  neuron  is 
applied  to  the  complete  nerve-unit,  that  is,  the  body  of  the 
cell,  and  all  its  branches.  The  cell  processes  are  said  to 
contain  Nissl's  granules,  but  we  have  it  on  the  authority 
of  Dr.  Mott  that  these  do  not  exist,  as  such,  in  the  living 
cell,  and  probably  not  therefore  in  the  living  dendron 
(seep.  190). 

Such  is  a  brief  physiological  description  of  the  dendrons 
and  the  processes  associated  with  them,  and  from  it  there 
does  not  at  first  sight  appear  to  be  any  intimate  connection 
between  them  and  the  synapses.  If,  however,  they  are 
considered  in  the  light  of  Cajal's  illustration  of  the  synaptic 
connections  of  sympathetic  cells  from  the  superior  cervical 
ganglion  of  man,  as  given  by  Schafer  (see  Fig.  90),  it 
will  be  seen  that  the  evidence  points  to  the  dendrons  being 
branch-circuits,  the  arborisations  having  the  function  of 
condensers,   or  Leyden  jars ;    each  synaptic  junction  or 


ANIMAL   AND   VEGETABLE  169 

dielectric  process  offering  resistance,  and  therefore  inter- 
posing delay  to  the  passage  of  the  current  or  impulse. 

Halliburton  has  told  us,  and  it  is  an  important  fact 
to  remember,  that  each  nerve-unit  is  anatomically  inde- 
pendent of  every  other  nerve-unit.  The  arborisations 
interlace  and  intermingle,  and  nerve  impulses  are  trans- 
mitted from  one  nerve-unit  to  another,  through  contiguous, 
but  not  through  continuous  structures.  Furthermore  it  is 
open  to  question  whether  a  so-called  continuous  current 
of  electricity  is  continuous  in  the  strictest  sense  of  the 
word,  or  whether  it  is  really  a  series  of  polarisations  and 
discharges  occurring  with  such  velocity  as  to  appear  to  be 
continuous. 

Put  shortly,  the  views  taken  of  the  propagation  of 
electric  force  by  molecular  action  consider  the  molecules  of 
the  interpolar  wire  to  be  as  follows  : — 


Wm  K  K 1^  K:  EEIPP^EK^C** 


C 

Fis.  89. 


c  being  the  copper  and  z  the  zinc  end,  the  shaded  parts 
being  +  and  the  unshaded  — .  The  first  effect  of  the 
electric  force  developed  by  the  chemical  affinity  of  the 
zinc  for  the  O  or  SO^  is  to  throw  all  the  molecules  of  the 
circuit  into  a  polar  condition,  the  force  being  transmitted 
from  molecule  to  molecule  in  both  directions.  Positive  and 
negative  electricities  appear  in  each  molecule  of  the 
circuit  ;  and  if  the  action  be  powerful  enough,  discharge 
takes  place  throughout  the  whole,  each  molecule  giving  out 
its  electricities  to  those  next  it,  which,  throwing  out  the 
opposite  electricities,  produce  electric  quiescence  through- 
out. A  constant  series  of  such  polarisations  and  dis- 
charges, taking  place  with  enormous  rapidity,  constitute 
a  current. 

In  the  body  the  impulse  may  be,   and  probably  is, 


170       STUDIES   IN   ELECTRO -PHYSIOLOGY  : 

induced  in  and  not  transmitted  through  a  contiguous 
structure,  in  the  same  manner  that  a  current  passing  along 
one  insulated  wire  may  induce  a  current  in  another^ 
contiguous  but  not  continuous,  insulated  wire  ;  of  opposite 
sign  understood. 

The  following  is  a  sketch  from  the  drawing  I  have 
mentioned : — 


Fig.  90.  {After  Cajal.) 

Synaptic  connections  of  a  sympathetic  cell  from  the  superior  cervical 
ganglion  of  man. 

A  =  cell  with  well-marked  intracapsular  dendrons  ;  C,  D  =  synapses 
between  dendrons  outside  the  cell  capsules  ;  a  =  axon ;  b,  d,  c,  e  =  extra- 
capsular dendrons. 

Let  us  assume  that  the  cell  A  is  the  source  or  container 
of  energy  and  that  D  is  a  typical  synapse  ;  I  say  D  because 
its  structure  is  more  clearly  marked  than  that  of  C. 


.-^ 


Fig.  91. 

Let  the  dark  lines,  c,  c,  c,  represent  conductors  ;  d,  d,  d,  non-conductors, 
and  e,  e,  connective  tissvie. 


ANIMAL  AND   VEGETABLE  ITl 

Furthermore,  we  will  draw  D  upon  a  larger  scale,  as  I 
imagine  it  to  be  (see  Fig.  91). 

We  can  have  no  doubt  that  c,  c,  c  are  conductors 
because  they  transmit  impulses  ;  d,  d,  d  must  be  dielec- 
trical  in  character,  as  they  are  designed  to  conserve  energy 
in  the  axon,  and  there  is  reason  for  the  belief  that  both 
neuroglia  and  connective  tissue  are  non-conducting  sub- 
stances. 

A  condenser,  as  used  in  telegraphy,  is  conventionally 
shown  in  illustration,  and  the 

analogy,   if   we  pursue    it,    is — — -J -" 

rather    remarkable.      In    the  „.    ^, 

Fig.  9lA. 

figure      only      the      conduct- 
ing plates  are  shown.     Let  us  insert  the  dielectric,  and 
the  synaptic  connection  appears  to  be  a  condenser  of  large 
surface-area,  but  possibly,  by  reason  of  the  points  or  pro- 
jections, of  comparatively  high  tension. 


£'-^ 


Fig.  92. 

According  to  Schafer,  the  "  arborisations  from  different 
cells  may  interlace  with  one  another  (as  in  the  olfactory 
glomeruli,  in  the  retina,  and  in  the  sympathetic  ganglia), 
or  a  terminal  arborisation  from  one  cell  may  embrace  the 
body  or  the  cell-processes  of  another  cell  ;  as  with  the  cells 
of  the  spinal  cord  and  the  cells  of  the  trapezoid  nucleus  of 
the  pons  Varolii,  and  in  many  other  places.  The  term 
neuro-synapse  may  be  applied  to  these  modes  of  junction. 
By  them  nerve-cells  are  linked  together  into  long  chains 
of  neurons,  the  physiological  path  being  uninterrupted, 
although  the  anatomical  path  is  believed  to  be  interrupted 
at  the  synapses." 


1T2      STUDIES   IN  ELECTRO-PHYSIOLOGY: 

From  this  it  would  appear  that  the  two  arborisations  as 
shown  in  the  enlarged  sketch  of  D  (Fig.  91 )  may  actually 
touch  or  embrace  each  other,  so  that  no  additional  resistance 
may  be  offered  by  intervening  connective  tissue,  but  even 
in  such  case  there  would  be  two  thicknesses  of  dielectric 
{d,  d)  to  one  of  conductor  (c)  in  the  path  of  the  impulse, 
and  the  result  must  be  delay  during  the  accumulation  of 
tension  at  the  arborisation  nearest  the  cell,  the  plates  being 
further  apart. 

As  the  cell  is  in  the  superior  cervical  region  two  things 
follow,  logically  :  i.e.  (1)  the  impulse  from  it  is  efferent, 
and  (2)  the  tension  in  the  dendron  is  comparatively  high. 
We  know  also  that  electricity  concentrates  upon  points  or 
projections,  and  the  arborisations  appear  to  be  constructed 
in  accordance  with  this  law. 

When  we  are  able  to  examine  the  structure  of  the 
brain,  I  think  the  evidence  in  support  of  the  human  organism 
being  neuro-electrically  controlled — with  consequent 
chemical  action — will  be  even  more  convincing  than  that 
I  have  already  adduced. 

One  thing  stands  out  prominently — and  it  cannot  be 
given  too  great  prominence — this  vital  action,  neuro- 
electrical  or  chemical,  or  both,  cannot  go  on  unimpaired  if 
the  natural  insulation  resistance,  in  any  part  of  the  body,  is 
broken  down  or  interfered  with. 

CONNECTION  OF  MUSCLES  AND  BONES,  etc. 

If,  in  addition  to  a  consideration  of  the  different 
behaviour  of  muscular  tissue  owing  to  differences  of  tension* 
quantity,  and  resistance,  we  unite  a  brief  survey  of  their 
connection  with  bones,  we  may  obtain  a  still  better  grasp  of 
the  subject.  As  a  considerable  number  of  muscle-fibres 
constitute  the  trunk  of  the  muscle,  strong  slender  threads 
of  the  nature  of  connective  tissue  unite  into  cords  which 


ANIMAL   AND   VEGETABLE  ITS 

are  called  the  muscle-tendons.  They  are  sometimes  short, 
sometimes  long,  thicker  or  thinner  according  to  the  size  of 
the  muscle,  and  they  serve  to  attach  the  muscles  firmly  to 
the  bones,  to  which,  acting  like  ropes,  they  transmit  the 
tension  of  the  muscles.  One  of  the  two  bones  to  which  a 
muscle  is  attached  is  usually  less  mobile  than  the  other, 
so  that  when  the  muscle  shortens,  the  latter  is  drawn  down 
against  the  former.  In  such  a  case  the  point  of  attachment 
of  the  muscle  to  the  less  mobile  bone  is  called  its  origin, 
while  the  point  to  which  it  is  fixed  on  the  more  mobile  bone 
is  called  its  attachment  {epiphysis).  For  instance,  there 
is  a  muscle  which,  originating  from  the  shoulder-blade  and 
collar-bone,  is  attached  to  the  upper  arm-bone  ;  when  this 
muscle  is  shortened  the  arm  is  raised  from  its  perpendicular 
pendant  position  into  a  horizontal  position.  A  muscle  is 
not  always  extended  between  two  contiguous  bones. 
Occasionally  passing  over  one  bone,  it  attaches  itself  to  the 
next.  This  is  the  case  with  several  muscles  which,  origin- 
ating from  the  pelvic  bone,  pass  across  the  upper  thigh-bone 
and  attach  themselves  to  the  lower  thigh-bone.  In  such 
cases  the  muscle  is  capable  of  two  different  movements : 
it  can  either  stretch  the  knee,  previously  bent,  so  that  the 
upper  and  the  lower  thigh-bones  are  in  a  straight  line,  or 
it  can  raise  the  whole  extended  leg  yet  higher  and  bring  it 
nearer  to  the  pelvis.  But  the  points  of  origin  and  of 
attachment  of  muscles  may  exchange  offices.  When  both 
legs  stand  firmly  on  the  ground  the  above-mentioned 
muscles  are  unable  to  raise  the  thigh  ;  instead,  on  shorten- 
ing, they  draw  down  the  pelvis,  which  now  presents  the 
more  mobile  point,  and  thus  bend  forward  the  whole 
upper  part  of  the  body.  ...  In  a  previous  examination 
of  the  action  of  muscle  we  have  dealt  with  an  imaginary 
muscle,  the  fibres  of  which  were  of  equal  length  and  par- 
allel to  each  other.  Such  muscles  do  really  exist,  but  they 
are  rare.     When  such  a  muscle  shortens,  each  of  its  fibres 


174      STUDIES   IN  ELECTRO-PHYSIOLOGY: 

acts  exactly  as  do  all  the  others,  and  the  whole  action  of 
the  muscle  is  simply  the  sum  of  the  separate  actions  of  all 
the  fibres.  As  a  rule,  however,  the  structure  of  muscles  is 
not  so  simple.  According  to  the  form  and  the  arrange- 
ment of  the  fibres,  anatomists  distinguish  short,  long,  and 
flat  muscles.  The  last  mentioned  generally  exhibit  devia- 
tions from  the  ordinary  parallel  arrangement  of  the  fibres. 
Either  the  fibres  proceed  at  one  end  from  a  broad  tendon, 
and  are  directed  towards  one  point  from  which  a  short 
round  tendon  then  effects  their  attachment  to  the  bones 
(fan-shaped  muscles),  or  the  fibres  are  attached  at  an  angle 
to  a  long  tendon,  from  which  they  all  branch  off  in  one 
direction  (semi-pennate  muscles),  or  in  two  directions  like 
the  plumes  of  a  feather  (pennate  muscles).  In  the  radiate 
or  fan-shaped  muscles  the  pull  of  the  separate  parts  takes 
effect  in  different  directions.  Each  of  these  parts  may  act 
separately,  or  all  may  work  together  ;  and  in  the  latter  case 
they  combine  their  forces,  as  is  invariably  the  case  with 
forces  acting  in  different  directions,  in  accordance  with  the 
so-called  parallelogram  of  forces.  As  an  example  of  this 
sort  of  muscle  the  elevator  of  the  upper  arm  (the  deltoid 
muscle)  may  be  examined.  Contractions  of  the  separate 
parts  really  occur  in  this.  When  onlj^  the  front  section  of 
the  muscle  contracts,  the  arm  is  raised  and  advanced  in 
the  shoulder-socket ;  when  only  the  posterior  part  of  the 
muscle  contracts,  the  arm  is  raised  backward.  When, 
however,  all  the  fibres  of  the  muscle  act  in  unison,  the 
action  of  all  the  separable  forces  of  tension  constitutes  a 
diagonal  which  results  in  the  lifting  of  the  arm  in  the  plane 
of  its  usual  position. 

"  In  some  semi-pennate  and  pennate  muscles  the  line  of 
union  of  the  two  points  of  attachment  does  not  coincide 
with  the  direction  of  the  fibres.  When  the  muscle  contracts 
each  fibre  exerts  a  force  of  tension  in  the  direction  of  its 
contraction.     All  these  numerous  forces,  however,  produce 


ANIMAL  AND   VEGETABLE  175 

a  single  force  which  acts  in  the  direction  in  which  the 
movement  is  reall}'  accomplished,  and  the  whole  action  of 
the  muscle  is  the  sum  of  these  separate  components,  each 
derived  from  a  single  fibre.  In  order  to  calculate  the  force 
which  one  of  these  muscles  can  exert,  as  well  as  the  height 
of  elevation  proper  to  it,  it  would  be  necessary  to  determine 
the  number  of  the  fibres,  the  angle  which  each  of  these 
makes,  with  the  direction  finally  taken  by  the  compound 
action,  as  well  as  the  length  of  the  fibres — these  not  being 
always  equal.  .  .  .  The  direction  in  which  the  action  takes 
effect  does  not,  however,  depend  only  on  the  structure  of 
the  muscle,  but  chiefly  on  the  nature  of  its  attachment  to 
the  bone.  Owing  to  the  form  of  the  bones  and  their 
sockets,  the  points  of  connection  by  which  the  bones  are 
held  together,  the  bones  are  capable  of  moving  only  within 
certain  limits,  and  usually  only  in  certain  directions.  For 
instance,  let  us  watch  a  true  hinge- socket,  such  as  that  of 
the  elbow,  which  is  capable  only  of  bending  and  stretching. 
As,  in  this  case,  the  natm'e  of  the  socket  is  such  that  motion 
is  only  possible  in  one  plane,  the  muscles  which  do  not  lie 
in  this  plane  can  only  bring  into  action  a  portion  of  their 
power  of  tension,  and  this  may  be  found  if  the  tension 
exercised  by  the  muscle  is  analysed  in  accordance  with  the 
law  of  the  parallelogram  of  forces,  so  as  to  find  such  of  the 
component  forces  as  lie  within  the  plane."  (Rosenthal,  1895.) 

Here  it  may  be  useful  to  give  a  brief  description  of  what 
is  meant  by  the  parallelogram  of  forces,  my  authority 
being  Dr.  M'Gregor-Robertson. 

Let  O,  in  the  figure  on  next  page,  be  a  particle  under  the 
influence  of  two  forces,  one,  OB,  urgmg  it  in  the  direction 
of  B,  and  the  other,  OA,  urging  it  in  the  direction  of  A. 
It  is  evident  that  the  particle  cannot  proceed  along  either 
path,  but  will  choose  a  path  which  is  a  compromise  between 
the  two.  It  will  move  upwards.  Let  a  third  force, 
represented  by  the  weight,  be  applied  to  O,  and  let  this 


176       STUDIES  IN  ELECTRO-PHYSIOLOGY  i 

third  force  be  adjusted  so  that  O  remains  in  its  original 
position,  and  suppose  the  weight  to  represent  a  force  of 
1  lb.     Then  O  is  under  the  influence  of  three  forces  ;   but  it 


Fig.  93. 

is  at  rest,  so  that  the  forces  are  in  equilibrium.  The  forces 
OA  and  OB  are  both  tending  to  draw  O  upwards,  and  they 
are  completely  counterbalanced  by  the  1  lb.  weight.  To 
put  it  another  way,  the  weight  is  tending  to  pull  O  down- 
wards, but  is  counterbalanced  by  OA  and  OB.  But  the 
weight  would  be  counterbalanced  exactly  by  a  force  of 
1  lb.  acting  in  the  direction  directly  opposed  to  it,  that  is, 
in  the  direction  of  the  straight  line  drawn  up  from  O.  If, 
therefore,  OA  and  OB  be  withdrawn,  and  one  force  sub- 
stituted equal  to  the  weight  opposing  them,  equilibrium 
will  still  be  maintained.  So  the  two  forces  OA  and  OB 
can  be  replaced  by  a  single  force,  which  is  called  the  resultant 
force.  If  a  parallelogram  be  constructed  on  OB,  OA,  as 
indicated  in  the  following   figure,  it  wUl  be  seen  that  the 


Fig.  94. 

resultant  force  is  the  diagonal  of  the  parallelogram.     The 
two  forces  OA,  OB,  are  acting  on  a  particle.     To  find  the 


ANIMAL   AND    VEGETABLE  177 

direction  in  which  the  particle  will  move,  a  parallelogram  is 
constructed  of  which  OA  and  OB  form  two  sides,  and  then 
the  diagonal  OR  of  the  parallelogram  is  drawn.  It  gives 
the  direction  which  the  particle  takes  ;  it  is  the  resultant  of 
the  two  forces  OA,  OB  ;  and  if  the  lines  OA  and  OB  repre- 
sent by  their  lengths  the  magnitude  of  the  forces,  then  the 
diagonal  will  represent  bj'^  its  length  the  magnitude  of  the 
resultant  force.     This  is  the  parallelogram  of  force. 

In  a  similar  way  one  force  may  be  made  to  take  the 
place  of  several  forces.  Let  a  parallelogram  be  constructed 
on  the  lines  representing  two  of  the  forces.  Take  the 
diagonal,  and  with  it  and  the  line  representing  the  third 
force  construct  another  parallelogram.  Its  diagonal  is 
the  resultant  of  the  three  forces  ;  with  it  and  the  line 
representing  the  fourth  force,  the  resultant  of  four  forces 
may  be  found,  and  so  on. 

"  It  is  different  in  the  case  of  the  more  free  ball-sockets, 
which  permit  movement  of  the  bone  in  any  direction 
within  certain  limits.  When  a  socket  of  this  sort  is  sur- 
rounded by  many  muscles,  each  of  the  latter,  if  it  acts  alone» 
sets  the  bone  in  motion  in  the  direction  of  its  own  action. 
If  two  or  more  of  the  muscles  assum^e  a  state  of  activity  at 
the  same  time,  then  the  action  will  be  the  resultant  of  the 
separate  tensions  of  each, 

"  There  is  yet  another  way  in  which  the  work  performed 
by  the  muscles  is  conditioned  by  their  attachment  to  the 
bones.  The  latter  must  be  regarded  as  levers  which  turn 
on  axes,  afforded  by  the  sockets.  They  usually  represent 
one-armed,  but  sometimes  two-armed  levers.  Now,  the 
direction  of  the  tension  of  the  muscles  is  seldom  at  right 
angles  to  that  of  the  movable  bone  lever,  but  is  usually  at 
an  acute  angle.  In  this  case,  again,  the  whole  tension  of 
the  muscle  does  not  take  effect,  but  only  a  component, 
which  is  at  right  angles  to  the  arm  of  the  lever.  Now,  it  is 
noticeable  that  in  many  cases  the  bones  have  projections 

N 


178       STUDIES    IN   ELECTRO-PHYSIOLOGY: 

or  protrusions  at  the  point  of  attachment  of  the  muscles, 
over  which  the  tendon  passes,  as  over  a  reel,  thus  grasping 
the  bone  at  a  favourable  angle  ;  or,  in  other  cases,  it  is 
found  that  cartilaginous  or  bony  thickenings  exist  in  the 
tendon  itself  (so-called  sesamoid  bones),  which  act  in  the 
same  way.  The  largest  of  these  sesamoid  bones  is  that  in 
the  knee,  which,  inserted  in  the  powerful  tendon  of  the 
front  muscle  of  the  upper  thigh,  gives  a  more  favourable 
direction  to  the  attachment  of  this  tendon  than  there 
would  otherwise  be."     (Rosenthal.) 

I  have  quoted  at  considerable  length  from  Professor 
Rosenthal,  but  his  explanation  of  the  connection  of  muscles 
with  bones  is  so  lucidly  given,  that  while  I  may  be  in  need 
of  his  forgiveness  I  owe  no  apology  to  my  readers  for  the 
digression.  The  measure  of  my  offence  is,  however,  not 
ended.  So  far  we  have  been  dealing  with  voluntary 
muscle.  It  now  remains  to  examine  plain  muscle  in  respect 
of  which  physiological  works  in  general  are  comparatively 
silent.  We  are  told  that  they  are  longitudinally  but  not 
transversely  striated,  and  I  cannot  reconcile  this  with 
"  shortening  and  broadening  "  due  to  the  electrical  law  of 
attraction  and  repulsion.  This,  however,  we  will  consider 
in  its  proper  place. 

RESPONSE    OF   HUMAN  MUSCLES   AND   NERVES 
TO  ELECTRICAL  STIMULATION 

As  this  has  an  important  bearing  upon  the  theoretical 
explanation  I  have  so  far  given  of  the  electro-physiology 
of  the  motor  apparatus,  it  may  be  permissible  to  quote 
and  comment  upon  Halliburton.  He  says  :  "  When  the 
nutrition  of  the  nerves  is  impaired  much  stronger  currents 
of  both  the  induced  and  constant  kinds  are  necessary  to 
evoke  muscular  contractions  than  in  the  normal  state." 

If  for  "  nutrition  "  we  read  "  conductivity  "  comment 
is  unnecessary. 


ANIMAL   AND   VEGETABLE  179 

"  When  the  nerves  are  completely  degenerated  (as,  for 
instance,  when  they  are  cut  off  from  the  spinal  cord,  or 
when  the  cells  in  the  cord  from  which  they  originate  are 
themselves  degenerated,  as  in  infantile  paralysis),  no 
muscular  contraction  can  be  obtained  on  stimulating  the 
nerves,  even  with  the  strongest  currents." 

Obviously,  there  is  a  complete  loss  of  conductivity. 
In  the  old  days  the  cables  laid  in  South  American  waters 
were  insulated  with  india-rubber.  The  sulphur  in  the 
rubber  caused  rapid  degeneration  of  the  conductors,  and 
the  application  of  1,000,000  volts  at  A  would  not  cause  a 
receiving  instrument  at  B  to  contract,  by  reason  of  a  break 
or  breaks  of  continuity. 

"  The  changes  in  the  excitability  of  the  muscles  are  less 
simple,  because  in  them  there  are  two  excitable  structures, 
the  terminations  of  the  nerves  (end-organs)  and  the  mus- 
cular fibres  themselves." 

It  is  open  to  question  whether  the  end-organs  are  not 
inducing  bodies.  Nowhere  do  they  appear  to  make  actual 
contact ;  that  is  to  say,  they  do  not  connect  as  wires  are 
connected  so  that  a  direct  current  flows  through  them,  but 
appear  to  act  inductively  upon  the  organs  they  influence. 

"  Its  excitabilit}^  "  (that  of  muscle)  '*  corresponds  in 
degree  to  that  of  the  nerve  supplying  it." 

In  accordance  with  Ohm's  law  the  degree  of  excitability 
of  the  muscle  would  be  governed  by  the  resistance  of  the 
motor  nerve  supplying  it. 

"  The  fact  that,  under  normal  circumstances,  the  con- 
traction which  is  caused  by  the  constant  current  is  as  quick 
as  that  produced  by  an  induction  shock,  is  ground  for 
believing  that  in  health  the  constant,  like  the  induced 
current,  causes  the  muscle  to  contract  chiefly  by  exciting 
the  motor  nerves  within  it." 

Tensions  being  equal,  the  effect  of  an  induction  shock 
is  not,  cannot  be,  the  same  as  the  effect  produced  upon 


180       STUDIES   IN    ELECTRO-PHYSIOLOGY: 

muscle  by  an  impulse  originating  in  a  constant  or  direct 
current  of  normal  potential.  In  both  cases  the  motor 
nerves  convey  the  impulse  or  impulses  to  muscular  fibres, 
but  the  muscular  response  cannot,  in  my  judgment,  be 
identical. 

"  When  the  motor  nerve  is  degenerated,  and  will  not 
respond  to  any  form  of  electrical  stimulation,  the  muscle 
loses  all  its  power  of  response  to  induction  shocks.  The 
nerve-degeneration  is  accompanied  by  their  rapid  wasting, 
and  any  power  of  response  tofaradism  they  possessed  in  the 
normal  state  is  lost." 

That  naturally  follows. 

"  But  the  response  of  the  muscle  to  the  constant 
current  remains,  and  is,  indeed,  more  ready  than  in  health." 

The  meaning  here  is  somewhat  obscure.  If  it  is  sought 
to  convey  the  constant  current  to  the  muscle  by  means  of 
the  degenerated  motor  nerve,  and  there  is  a  complete  break 
of  continuity,  no  current  could  pass  and  no  response  be 
given.  If,  however,  the  sarcomeres  are  stimulated  directly 
the  normal  resistance  of  the  motor  nerve  would  be  elimi- 
nated and  the  muscle  should  certainly  give  a  readier 
response.  This  may  be  what  is  meant,  because  we  have 
been  told  that  "  when  the  motor  nerve  is  degenerated  and 
will  not  respond  to  any  form  of  electrical  stimulus  the  muscle 
loses  all  its  power  of  response  to  induction  shocks."  But 
the  phenomenon  may  be  due  to  the  end-organs,  as  well  as 
the  motor  nerve-fibres,  transforming  or  modifying  in 
normal  health  an  induction  shock — a  momentary  impulse — 
so  that  the  muscle  could  respond  to  it,  and  that  after 
degeneration  no  such  modification  could  occur. 

"  Suppose  a  patient  comes  before  one  with  muscular 
paralysis.  This  may  be  due  to  disease  of  the  nerves,  of  the 
cells  of  the  spinal  cord,  or  of  the  brain.  If  the  paralysis  is 
due  to  brain  disease,  the  muscles  will  be  slightly  wasted 
owing    to    disuse,    but    the    electrical    irritability    of   the 


ANIMAL   AND   VEGETABLE  181 

muscles  and  nerves  will  be  normal,  as  they  are  still  in 
connection  with  the  nerve  cells  of  the  spinal  cord  which 
control  their  nutrition." 

True.  But  where  does  the  impulse  originate,  nor- 
mally ?  In  a  nerve  cell  or  cells  in  the  motor  area  of  the 
brain.  If  that  cell  or  those  cells  fail  to  act,  no  impulse  can 
pass  from  brain  to  muscle.  In  other  words,  the  rest  of 
the  apparatus  is  in  working  order,  but  some  of  the  battery 
cells  have  given  out. 

"  But  if  the  paralysis  is  due  to  disease  either  of  the 
spinal  cord  or  of  the  nerves,  this  nutritive  influence  can  no 
longer  be  exercised  over  the  nerves  or  muscles." 

Of  course  not.  There  is  a  partial  or  total  loss  of 
conductivity  by  reason  of  the  influence  of  disease  upon  the 
spinal  cord  or  the  nerves.  The  motor  apparatus  generally 
may  be  in  working  condition,  but  no  energy  can  be  con- 
vevcd  to  it,  and  it  cannot,  therefore,  be  set  in,  motion. 


182      STUDIES   IN   ELECTRO-PHYSIOLOGY 


Chapter   XII 

CARDIAC    MUSCLE 

The  problem  of  the  structure  and  precise  function- 
ing of  cardiac  muscle  is  not  easy  of  solution,  owing,  in 
the  main,  to  the  absence  of  diagrams  illustrating  its 
connections.  Several  facts,  however,  stand  out  promin- 
ently. 

It  is  said  (1)  to  be  intermediate  in  structure  and 
properties   between   voluntary   and   involuntary   muscle ; 

(2)  to  contract  more  slowly  than  ordinary  striped  muscle  ; 

(3)  to  be  striated  ;  and  (4)  to  have  no  true  sarcolemma, 
"  although  there  is  a  thin  superficial  layer  of  non-fibrillated 
substance."     (Schafer.) 

Considering,  as  we  must  do,  each  segment  as  a  sarco- 
mere, it  will  be  seen  that  the  segments  differ  in  length  and 
in  diameter  (permitting  of  infinite  variation  of  tension)  ; 
that  some  are  non-nucleated,  and  that  there  are  branch,  or 
shunt,  circuits  which  no  doubt  play  their  part  in  the 
inductive  regulation  of  tension  in  an  automatic  neuro- 
electrieal  system,  because,  although  the  heart's  action 
may  be  subject  to  psychological  influences,  it  must 
be  supplied,  from  within  or  without,  with  energy  un- 
intermittently,  and  therefore  must  form  part  of  an 
automatic  system. 

And  here,  perhaps,  we  may  begin  to  appreciate  the 
beautiful  regulation  exercised  by  the  vagus  nerves.  The 
energy,   partly   self-contained  or    not,   which,   in  life,   is 


ANIMAL  AND    VEGETABLE  188 

constantly  supplied  to  the  heart,is  by  way  of  the  sympathetic, 
while  the  vagus  nerves  are  inhibitory,  or,  in  other  words, 
exert  a  governing  or  opposing  electromotive  force.  They 
are  buffers,  or  springs,  regulating  the  flow  of  energy  to  the 
heart,  much  in  the  same  way  that  a  rise  or  fall  of  tempera- 
ture may  regulate  the  fall  or  rise  of  a  gas-flame  in  a  heating 
apparatus. 

We  learn,  from  physiological  research,  that  man  inhales 
400  c.c.  of  oxygen  per  minute  during  the  daytime  and 
200  c.c.  per  minute  during  the  night.  I  know,  from  my 
own  work,  that  if  the  hand-to-hand  galvanometric  deflec- 
tion of  a  normally  healthy  man  during  the  daytime  is 
850  mm.  it  will  fall  at  night  to  about  175  mm. 

That  means  there  is  a  falling  off  in  the  production  or 
reception  of  nervous  energy  of  fifty  per  cent. 

But  the  controlling,  governing  current  from  the  brain 
— the  inhibiting  current — is  also  halved,  because  generation, 
or  reception,  is  halved,  and  therefore  there  is  no  alteration 
in  equilibrium,  and  the  heart  must  receive  a  proportionate 
supply  of  energy  at  all  times,  supposing  there  to  be  no 
escape  of  nerve-current  or  excitement  of  the  vagi.  Should 
such  an  escape  occur,  the  result,  or  one  result,  should  be 
higher  blood-pressure,  while  in  the  event  of  anything,  such 
as  cold  or  some  toxin,  increasing  the  resistance  of  the 
conducting  substance  of  the  vagi,  the  same  phenomenon 
should  bepresentedjbecause  inhibition  would  be  diminished. 
On  the  other  hand,  any  cerebral  disturbance  tending  to 
unduly  stimulate  the  cardiac  branches  of  the  vagi  would 
have  the  effect  of  slowing  the  heart  down,  possibly  in 
extreme  cases  to  a  fatal  extent. 

The  main  differences,  so  far  as  I  can  see,  between 
voluntary  and  cardiac  muscles  are  :  (1)  the  first  are  supplied 
by  open  circuits  through  which  impulses  are  sent  from  the 
brain  ;  (2)  cardiac  muscles  form  part  of  a  closed  circuit 
or  circuits  regulated  by  cell-groups  possibly  other  than 


184      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

unipolar  ;  (3)  voluntary  muscles  contract  in  parcels  of 
sarcomeres  and  not  necessarily  in  one  direction  ;  and  (4) 
cardiac  muscles  contract  in"  walls,"  rhythmically,  and  as 
the  rate  of  propagation  of  the  wave  is  slower  than  in 
voluntary  muscles,  their  inductive  capacity,  and  possibly 
their  resistance,  must  be  greater,  probably  by  reason  of  the 
conducting  surfaces  being  connected,  mainly  if  not  en- 
tirely, in  parallel  (see  also  p.  94). 

Plain  Muscle 


In  regard  to  plain  muscle  there  is,  as  I  have  remarked 
elsewhere,  a  lack  of  information.  To  my  mind  there  can 
be  no  manner  of  doubt  that  they  are  transversely  striated, 
although  the  striae  are  too  small  to  be  clearly  observed. 
I  am  forced  to  this  conclusion  by 
several  considerations,  one  of  which 
is  that  it  is  difficult  to  conceive  how 
they  can  shorten  and  broaden  if  only 
longitudinally  striated.  They  would 
flatten  but  not  shorten.  Professor 
Rosenthal  says  :  "  It  must  be  observed, 
that  the  distinction  between  striated 
and  smooth  muscle-fibres  is  not  abso- 
lute ;  for  there  are  transitionary  forms, 
such  as  the  muscles  of  molluscs.  The 
latter  consist  of  fibres,  exhibiting  to 
some  extent  a  striated  character,  and, 
in  addition  to  this,  the  character  of 
double  refraction.  At  these  points 
the  disdiaclasts  are  probably  arranged 
regularly  and  in  large  groups,  while  at 
other  points  (as  in  true  smooth  muscle- 
fibres)  they  are  irregularly  scattered  and  are  therefore  not 
noticeable." 


Fig.  95. — MuscuLAB 

Fibre-Celi  from  the 

Muscular    Coat     of 

THE  Small  Intestine. 

(After  S chafer.) 


ANIMAL   AND   VEGETABLE  185 

Nor  does  Schafer  really  commit  himself  definitely  to 
the  statement  that  plain  muscle  is  not  transversely  striated. 
He  says  :  "  Plain  muscular  tissue  is  composed  of  long, 
somewhat  flattened,  fusiform  cells  which  vary  much  hi 
length. 

"  Each  cell  has  an  oval  or  rod-shaped  nucleus,  which 
shows  the  usual  intra-nuclear  network,  and  commonly  one 
or  two  nucleoli.  The  cell-substance  is  finely  fibrillated, 
but  does  not  exhibit  cross-striae  like  those  of  voluntary  musck' 
There  appears,  as  in  cardiac  muscle,  to  be  a  delicate  non- 
striated  external  layer,  probably  a  stratum  of  undifferen- 
tiated protoplasm,  certainly  not  a  true  sarcolemma.  .  .  . 
There  is  a  little  intercellular  substance  which  is  bridged 
across  by  filaments  passing  from  cell  to  cell.  Some 
authorities,  however,  deny  that  the  involuntary  cells  are 
thus  connected,  and  hold  that  the  appearance  of  bridging 
fibres  is  due  to  intercellular  connective  tissue.  It  is, 
however,  difficult  to  understand  how  the  contractions  are 
propagated  from  cell  to  cell  if  there  is  no  sort  of  continuity 
between  the  cells.""  * 

Now,  in  regard  to  the  speculative  explanation  I  am 
about  to  give,  it  is  very  necessary  to  remember  that  this 
tissue  responds  but  slowly  to  a  stimulus,  and  that  the 
contraction  spreads  as  a  wave  from  fibre  to  fibre.  If  we 
depart  from  the  theory  of  condenser-action  the  problem 
must,  so  far  as  I  am  concerned,  remain  without  attempt  at 
solution,  but  if  we  adhere  to  it  we  may  begin  to  see  day- 
light. 

These  fibres  of  involuntary  muscle  are,  admittedly, 
longitudinally  striated.  They,  however,  contract  and 
become  shorter  and  broader.  It  is  quite  evident  that 
with  condenser-action  and  longitudinal  striation  only  they 
would  merely  flatten  (Figs.  96^  97) : — 

*  The  italics  are  mine. 


186      STUDIES  IN  ELECTRO -PHYSIOLOGY 


Fig.  96. 
Before  contraction. 


Fig.  97. 
During  contraction. 


whereas,  I  take  it,  what  really  happens  is  this,  roughly  : — 


Fig.  98. 
Before  contraction. 


Fig.  99. 
During  contraction. 


For  this  to  occur  it  is  not  at  all  necessary  for  the  fibres 
to  be  transversely  striated  as  voluntary  muscle  is  striated. 
All  that  is  required  is  that  they  should  possess  something 
of  the  nature  of  an  elastic  sarcolemma — and  the  external 


ANIMAL  AND   VEGETABLE 


187 


layer  must  be  elastic  to  permit  contraction — and  that 
they  should  be  bridged  at  intervals  by  some  non-conducting 
substance,  possibly  connective  tissue.  Condenser-action 
would  then  take  place  as  in  voluntary  tissue,  and  the  rate 
of  propagation  of  the  impulse  would  be  governed  by  the 
considerations  set  forth  in  the  chapter  upon  Inductive 
Capacity. 

In  this  manner  we  can  perceive  how  the  contraction 
spreads  as  a  wave  from  fibre  to  fibre,  and  why  it  is  that  the 
cells  vary  much  in  length.  They  also,  no  doubt,  vary  much 
in  diameter  in  order  to  enable  the  tension  to  be  varied, 
but  there  is  this  essential  difference,  I  think,  between 
voluntary  and  plain  muscle  :  the  former  is  required  to 
contract  in  curves,  at  different  velocities  in  the  course  of 
those  curves  and  not  in  the  same  direction  throughout, 
while  the  function  of  the  latter  is  merely  to  shorten. 

If  that  is  so  a  less  complicated  form  of  fibre  would  serve 
the  purpose,  nor  would  the  complex  end-organ  connec- 
tions be  necessary.  We  cannot  compare  the  cells,  for 
reasons  I  have  given,  to  a  chain  of  condensers  in  series, 

i.e.     ^^'  \  I j  I j  j 1 1  ^~^  ,  but  must  imagine  them 

to  be  connected  in  parallel  or  series-parallel.  Nor  is 
this  opinion  without  warrant,  as  the  following  figure  goes 
to  show  : — 


Fig.  100. — Muscle-Cells  of  Intestine  (Szymonowicz),  magnified 
530  Diameters.  (After  Schdfer.) 


188      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

"  The  fuily-formed  muscle  retains  its  syncytial  char- 
acter, and  is  not  formed  by  completely  separated  cells." 
(Schafer.) 

In  conclusion,  my  considered  opinion  is  that  while 
plain  muscle  is  not  transversely  striated  in  the  sense  that 
voluntary  muscle  is  transversely  striated,  the  longitudinal 
fibres  are  bridged  across  by  some  non-conducting  substance* 
and  that  the  chief  difference  in  the  structure  of  the  two  is 
the  absence  in  the  former  of  the  sarcous  element.  As, 
however,  the  charge,  instead  of  being  neutralised  at 
various  points,  passes  as  a  wave  from  cell  to  cell,  the 
sarcous  element  can  naturally  be  dispensed  with. 


ANIMAL  AND   VEGETABLE  189 


Chapter   XIII 

NISSL  S  GRANULES 

That  many  of  the  nerve  cells,  if  not  all  of  them,  contain 
organically  combined  iron,  as  suggested  by  Macaiium,  I  do 
not  doubt,  but  the  weak  link  which  has  hitherto  existed 
in  my  chain  of  reasoning  has  been  the  manner  in  which 
Nissl's  granules — so-called — have  been  shown,  in  physio- 
logical and  histological  works,  to  be  distributed  in  the  cell 
contents. 

As  will  be  seen  from  Figs.  109, 110  (taken  from  Schafer)* 
they  appear  as  masses,  and  this  is  not  quite  consistent 
with  the  theory  that  neuro-electricity  is  generated  by  the 
association  of  iron  with  oxygen  in  the  protoplasm.  One 
would  expect  to  find  iron  in  the  form  of  minute  particles 
arranged  in  the  cell  contents  in  a  well-defined  manner ; 
a  manner  which,  if  it  could  be  seen  with  a  sufficiently  high 
power,  would  make  it  clear  how  electrical  attraction  and 
repulsion  as  well  as  generation  are  brought  about.  In 
health  not  only  does  the  nucleus  occupy  a  central  position 
in  the  cell,  but  the  nucleolus  is  more  or  less  centrally 
situated  in  the  nucleus,  and  this  phenomenon,  as  well  as 
that  of  amoeboid  movement,  would  seem  to  have  its  origin 
in  electrical  activities  and  to  be  in  accordance  v/ith  the 
experiments  of  Ampere. 

With  iron  in  the  shape  of  irregular  masses  it  is  difficult 
to  see  how  this  harmonious  result  is  arrived  at,  no  matter 
how  convinced  we  may  be  that  it  is  so. 

The  illustrations  to  which  jl  have  referred  were  based 


190      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

upon  experiments  with  dead  cells,  and  I  have  always 
contended  that  the  difference  between  the  living  and  the 
non-living  is  so  great  as  to  render  results  with  the  latter 
not  only  almost  nugatory  but  often  misleading. 

The  valuable  work  of  Dr.  Mott,  however,  has  thrown 
new  light  upon  the  subject  and  helped  to  make  clear  that 
which  was  previously  obscure.  He  has  found  that  the 
basophile  staining  substance  which  forms  the  Nissl  granules 
does  not  exist  as  such  in  the  living  cells,  but  is  the  result 
of  coagulation.  "  If  living  cells  are  examined  micro- 
scopically with  dark-ground  illumination  they  are  seen  to 
be  filled  with  small  granules  or  globules,  each  of  w^hich, 
after  escaping  from  the  cell,  remains  discrete. 


Fig.  101. — Drawing  of  an'^Anterior  Horn  Cell,  with  Prockssbs. 

{After  Mott.) 

"  They  are  refractile,"  says  Mott,  "  and  appear  white 
and  luminous  ;  this  is  due  to  a  delicate  covering  film  of  a 
lipoid  substance  which  encloses  a  colloidal  fluid,  probably 
consisting  of  a  solution  of  salts  and  ceU  globulins.  When 
the  cell  dies  this  colloidal  fluid  is  massed  together  in  little 
blocks — the  Nissl  granules  ;  the  intervening  denser  colloidal 
substance  is  continuous  with  the  colloidal  substance  of 
the  axon  and  dendrons.  ...  It  thus  appears  possible  that 
these  granules  represent  a  large  oxygen  surface,  like 
spongy  platinum,  within  the  cell.  When  the  cells  die,  the 
lipoidal  film  of  the  globulin  containing  fluid  is  destroyed, 
coagulation  occurs,  and  the  Nissl  granules  are  formed. 
These  facts  accord  with  the  knowledge  that  stimulation  of 


ANIMAL  AND   VEGETABLE  191 

a  piece  of  nerve  causes  practically  no  metabolic  change  or 
using  up  of  oxygen,  therefore  the  mere  conduction  of  a 
stimulus  along  a  nerve  does  not  entail  loss  of  neuro- 
potential.  The  chemical  processes  incidental  to  the 
using  up  of  nervous  energy  in  the  neuron  take  place  in  the 
cell  itself,  and  it  is  for  this  reason  that  the  blood  supply  of 
the  grey  matter  is  six  times  that  of  the  white  matter." 

All  this,  coming  as  it  does  from  a  great  pathologist,  is 
strongly  in  favour  of  the  opinions  I  hold. 


192       STUDIES  IN  ELECTRO-PHYSIOLOGY 


Chapter  XIV 

THE   NODES   OF   RANVIER 

In  these  the  axis -cylinder  is  invariably  shown  as  passing 
in  an  uninterrupted  course  through  the  node,  but  although 
it  is  highly  speculative  and  daring  to  say  so,  I  doubt 
whether  this  is  the  case  functionally,  although  we  must 
believe  it  to  be  so  anatomically.  The  following  illustration 
is  a  typical  one  : — 


Fig.  102. — Medullated  Nekve-Fibre  showing  Fibrils  of  Axis 
Cylinder  (Bethe).  The  fibrils  are  seen  passing,  without  interruption, 
across  a  node  of  Ranvier.  (After  G.  N.  Stewart.) 

Now,  these  nodes  occur  at  regular  and  innumerable 
intervals  along  the  course  of  an  axis-cylinder,  but  their 
function  appears,  so  far  as  my  reading  goes,  to  be  im- 
perfectly understood.  If,  unlike  their  prototypes  in  the 
bamboo  and  the  sugar-cane,  the  axis-cylinder  is  struc- 
turally continuous  throughout  its  course,  they  do  not  seem 
to  serve  any  useful  purpose.  If,  on  the  other  hand,  there  is 
a  species  of  synapse  at  each  node,  their  purpose  and  function 


ANIMAL  AND   VEGETABLE  19^ 

become  at  once  apparent,  for  they  would  afford  protection 
to  the  axon  against  extensive  degeneration  consequent 
upon  injury. 

Let  us  examine  a  node  in  a  piece  of  bamboo. 
According  to   Strasburger  there   is  a 
wax  incrustation,  in  the  form  of  small  'A . 

rods,  at  a,  h.     The  interior  of  the  stem, 
between  the  nodes,  is  filled  with  a  soft  H-- -----.#* 

sponge-like  substance  which,  while  the        ji?Pt---'oSS  / 
plant  is  alive,  transmits  electricity — each     ^  ^M"' 
internode   indeed  seems  to  bear    some  W 

resemblance  to  a  cell — so  that  the  line 
a,   6,  notwithstanding  the  wax  incrusta- 
tion,   does    not     involve    a    break     of  p.     j^g 
continuity.     That    being    so,    it    would 
appear    that   the  node   is  of   the  nature  of   a    synapse, 
and   that  if  the  current  is  not   inductively   transmitted 
there  is  considerable  added  resistance  at  each  node. 

These  nodes,  be  it  remarked,  occur  at  regular  intervals 
upon  the  stems  of  bamboo  (all  canes)  and  sugar-cane,  in 
much  the  same  way  as  they  do  along  the  course  of  human 
nerves. 

In  the  nodes  of  Ranvier  the  line  a,  h  is  absent,  and  it 
does  not  necessarily  follow  because  a  colouring  matter  like 
picro-carmine  diffuses  into  the  fibre  only  at  the  nodes,  and 
stains  the  axis-cylinder  red,  while  it  does  not  diffuse 
through  the  white  substance  of  Schwann,  that  there  is  any 
difference  in  the  substance  of  the  axon  itself  at  those 
points. 

But  that  there  is  a  phase  in  the  nature  of  a  com- 
paratively high  resistance  across  the  line  a,  b  is,  I  think, 
more  than  probable  ;  for  this  reason  : — 

When  a  nerve  is  severed,  degeneration  in  the  proximal 
segment  takes  place  only  as  far  as  the  first  node  of  Ranvier. 

Consider  what,  from  an  electrical  point  of  view,  that 

o 


l94      STUDIES   IN  lELECTRO -PHYSIOLOGY  : 


a 


may  mean.  Let  us  take  two  nerves,  a  motor  and  a 
sensory,  and  see  what  would  happen  if  they  were  both 
severed  in  life. 

In  the  case  of  the  motor  nerve  the  battery  is  in  the 
brain  with  one  pole  to  earth  (air),  while  the  nerve — the 
wire,  as  it  were — is  also  to  earth  through  tissue  and  skin. 
The  effect  of  the  cut  is  to  remove 
the  conductor,  qua  conductor,  below 
the  node  immediately  above  the  cut 
and  to  an  imaginary  line  a,  h  (Fig.  104). 
The  whole  of  the  apparatus  above 
the  line  a,  h  would  be  structurally  and 
electrically  intact,  and  the  line  a,  h, 
if  of  high  resistance,  would  be  equiva- 
lent, in  hydrostatic  parlance,  to  a 
ligature  applied  to  an  artery  or  a  vein. 
Precedent  to  repair  or  regeneration 
of  the  lower  portion,  no  muscle  below 
the  cut  could  receive  an  impulse. 
If,  however,  the  axis-cylinder  were 
continuous  through  the  node  there  would  be  a  path  of 
low  resistance  at  the  node — an  escape  of  current  into  wet 
tissue — and  the  muscles  above  the  cut  could  only  receive 
stimuli  at  a  greatly  lowered  pressure. 

In  a  sensory  path  the  need  of  a  synaptic  node  is  even 
greater,  for  the  sensory  nerves  are  closed  circuits,  and  they 
have  many  ramifications  in  motor  as  well  as  other  sensory 
paths  over  which  they  transmit  impulses  in  various 
directions.  To  take  a  simple  sensory  path,  however,  from, 
say,  skin  to  post-spinal  ganglion. 

Here  we  have  a  charged  wire,  a  unipolar  guard-cell  or 
cells  to  maintain  normal  potential  in  that  wire,  and  a 
receiving  instrument  in  the  cord.  If  the  nerve  were  severed 
no  impulse  could  be  conveyed,  but,  given  the  line  of 
resistance  a,  6,  the  upper  part  of  the  nerve  from  the  first 


ANIMAL  AND   VEGETABLE  195 

node  above  the  cut,  together  with  the  unipolar  cells  and 
receiving  instrument,  would  be  in  working  order,  and  only 
that  portion  of  skin  in  connection  with  the  lower  part  of 
the  nerve  thrown  out  of  gear.  If,  however,  there  were  no 
line  of  resistance  at  the  node  above  the  cut,  all  the  circuits 
with  which  the  nerve  is  functionally  associated  would 
suffer,  the  nerve  and  the  cells  lose  their  charge,  and  the 
receiving  instrument  would  be  left  idle. 

It  is  inconceivable,  to  my  mind,  that  the  resistance  of 
the  axis-cylinder  is  not  greater,  much  greater,  at  the  nodes 
than  in  the  internodes,  but  as  a  matter  of  possibility  this, 
instead  of  involving  a  change  of  material,  may  be  created 
by  constriction  of  the  axon,  as  the  effect  of  constriction  in 
the  course  of  a  liquid  conductor  is  to  materially  lower 
conduction  at  that  point. 

In  some  works  the  nodes  are  called  *'  constrictions," 
and  the  suggestion  is  made  that  instead  of  the  constriction 
being  due  to  a  tightening  of  the  sarcolemma  it  is  effected 
by  a  band  (band  of  Ranvier)  which  compresses  the  axon. 
Row  this  may  be  I  do  not  know,  but  I  am  convinced  that 
in  whatever  manner  it  is  brought  about  there  is  con- 
denser-action or  similar  cause  of  delay  at  every  node. 


196      STUDIES  IN  ELECTRO-PHYSIOLOGY: 


Chapter  XV 

GANGLION  CELLS 

I  HAVE  stated  elsewhere  *  that  from  an  electrical  point 
of  view  some  ganglion  cells  are  condensers  and  some 
storage  cells,  but  this  statement  calls  for  elaboration.  In 
telegraphy — and  the  brain,  it  is  necessary  to  remember, 
both  sends  and  receives  messages — one  of  the  functions  of  a 
condenser  is  to  maintain  electrical  equilibrium,  and,  when 
required,  to  change  the  sign  of  current ;  whereas  the 
function  of  a  storage  cell  is  to  receive  a  charge  and  to  hold 
it  until  some  disturbance  of  neuro-electrical  equilibrium 
calls  for  its  deliverj^,  either  wholly  or  in  part.  In  this 
connection  let  us  consider  ganglion  cells  with  a  view  to 
attempting  to  differentiate  the  condenser  pure  and  simple 
from  the  storage  cell. 

Condenser-ganglion  cells  should  be  studied  more 
especially  in  relation  to  the  sympathetic  system,  the  nodes 
of  Ranvier  and  the  structure  of  the  muscles,  bearing  in 
mind  not  only  the  change  of  sign,  i.e.,  from  downward  to 
upward  current,  or  from  efferent  to  afferent,  but  control 
of  regularity  of  supply.  Assuming  there  to  be,  for  instance, 
a  flow  of  nerve-energy  of  a  certain  potential  from  the  brain 
(downwards)  along,  say,  the  sympathetic,  the  current 
strength  would  vary  with  the  resistances  in  circuit  in 
obedience  to  established  laws,  but  it  might  be  necessary  to 
regulate  both  current  strength  and  sign  at  different  points 
of  the  circuit.  Without  condenser -action  the  current 
would  have  to  reach  a  junction  and  return  by  a  nerve- wire, 

*  Electro-Pathology  and  Therapeutics. 


ANIMAL   AND   VEGETABLE 


197 


to  change  the  sign  from  efferent  to  afferent,  but  that  change 
could  be  more  rapidly  if  not  more  effectively  made  if  a 
condenser-ganglion  cell  of  the  proper  capacity  were  inserted 
in  position. 

Let  us  assume  that  we  had  a  downward  or  efferent 
current  from  the  brain  along  the  sympathetic — and  the 
argument  is  not  affected  if  we  suppose  an  upward  or 
afferent  current  to  the  brain — and  it  was  required  to  take 
off  at  various  points  an  upward  current  of  varying  strength. 
It  might  easily  be  done. 

In  the  following  diagram  the  thick  vertical  line  is 
intended  to  represent  the  chain  of  the  sympathetic — 


-jB rain  cell    ^-^X^ 


\/    + 


Con^^enser  |  JJTL 

c/fipiilse. 


-      + 


7^ 


-I 


y 


—  f^ihro'ht^h  reoi 


a  1 1  ___ 

^j[ Condenser 

j  i  ^iiHTT^  afferent 


■f 


-  £i/iro.  Ai^h  rtsLslance 


Fig.  105. 


Except  where  a  condenser  is  inserted  the  impulse  from 
the  brain  would  be  efferent,  and  its  current  strength  would 


198      STUDIES   IX  ELEC TRO -PHYSIOLOGY  : 

be  subject  only  to  Ohm's  law,  and  the  tension  to  the  lawi 
we  have  been  discussing.  If  at  any  point  it  was  desired 
to  alto:  the  sign  again  or  to  alt^r  the  t«ision.  the  insertion  of 
another  condens^-ganglion  ceU  of  the  required  plate-area 
in  CTCuit  would  do  it. 

The  diagrams  on  next  page.  Figs.  106, 107,  ill\istrating 
the  neurons  ci  the  motor  path  (after  Halliburton),  and 
a  similar  dectrieal  arrangement,  will  further  explain  my 
meaning. 

Study  of  the  physiological  diagram  will  show  that, 
conftHining  as  the  body  must  do  in  its  structure  to  estab- 
Udied  dectricai  laws,  the  source  of  energy^  i.e.,  the  cell  of 
the  cexdbral  grey  matter,  is  to  earth  (in  this  case  air)  in 
tiie  sanie  mann^  as  the  battery  in  the  electrical  diagram, 
while  eveiy  muscular  fibre  is  to  earth  (air)  through  the 
Sii::.  T*  it  is  desired  to  make  a  large  low-tension  motor- 
1-.  :  :^::polar.  and  to  transfarm  the  tension  therefrom 
ui^  ii  :.  it  is  only  necessary  to  provide  it  with  one,  or 
more,  additional  arborisation,  linking  by  induction  with 
one  oir  more  condeiKers  of  the  t]i-pe  of  h. 

Judging  by  their  effects,  we  might  believe  that  quantity 
and  t^ision  constitute  two  very  different  elements.  They 
are  in  reality  but  two  t(xms  of  the  same  thing.  The 
trai^oranation  of  quantity  into  tension  results  simply 
from,  the  mode  ol  distribution  of  the  same  energy-.  We 
realise  the  transformation  by  concentrating  the  energy 
within  a  vay  small  spac^  which  amounts  to  raising  its 
levd  above  that  of  the  zero  of  energy.  The  converse 
operaticm  will  transform,  on  the  contrary,  tension  into 
quantity.  A  coulomb  spread  over  a  sphere  of  10,000 
kiloDietres  radius  will  give  only  a  pressure  of  one  volt. 
Let  us  spread  the  same  quantity  of  electricity  over  a  sphere 
<rf  a  diameter  100,000  times  less — ^that  is  to  say,  of  100 
metres — and  this  same  quantity-  of  electricity  will  produce 
a  potential  a  hundred  thousand  times  higher — that  is  to 


ANIMAL  AND   VEGETABLE 


199 


Physiological. 


Electrical. 


earth 


~L-^JSafUry 


Fig.  106. 


{After  Halliburton.) 


Fig.  107. 


PCC  =  small  cells  at  the  base  of 
the  posterior  cornu. 

ACC  =  large  motor-cells  of  the 
anterior  cornu. 

M        =  muscular  fibres. 

PF      =  axon. 

CC  =  cell  of  the  cerebral  grey 
matter. 


aa     =  low-tension  condensers.]^ 
bhb    =  high-tension  condensers. 


200      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

say,  a  pressure  of  100,000  volts.  The  quantity  of  energy 
expended  has  not  been  varied,  only  its  distribution  altered. 
(Le  Bon.) 

In  this  light  we  may  ponder  several  forms  of  spinal 
ganglion  cells,  showing  the  cell  bodies,  the  afferent  sensory 
nerves,  and  the  dorsal  roots. 


M 


/p' 


y 


€i 


t 

3 

Fig.  108. 


a 


11 


{After  Landois  and  Stirling. 


To  my  mind  a,  c  are  nerves  carrying  storage  cells, 
which  would  hold  their  charge  unless  and  until  excessive 
mental  or  physical  exertion  had  disturbed  neuro-electrical 
equilibrium  in  the  sense  of  bringing  about  a  subnormal 
local  or  general  body  potential,  while  b  and  e  are  simple 
closed  circuits,  and  d  a  nerve  carrying  a  condenser.  Per- 
haps this  view  may  throw  some  further  light  upon  the 
subject  and  help  us  to  a  better  appreciation  of  the  functions 
of  ganglion  cells.  It  must  be  remembered,  however,  that 
the  due  functionment  of  both  ganglion  storage  and 
ganglion-condenser  cells  is  absolutely  dependent  upon  the 
maintenance  of  their  normal  insulation  resistance.  Should 
the  absolute  insulation  of  the  storage  cell  be  broken  down 


ANIMAL   AND   VEGETABLE  201 

to  any  extent  there  would  be  defective  storage,  and  if  the 
resistance  of  the  insulating  membrane  in  the  condensing  cell 
were  broken  down  or  altered  there  would  be  a  "  fault.*' 

In  works  upon  Physiology  confusion  is  caused  by  the 
uncertainty  which  attaches  to  the  meaning  of  the  words 
"stimulus,"  "impulse,"  "irritation,"  and  "charge" 
when  applied  to  nerve  cells,  but  if  it  be  accepted  that  the 
natural  impulse  is  neuro-electrical,  and  that  the  changes 
which  take  place  in  nerve-cells  and  processes  are  due  to 
alteration  of  nerve  potential,  sign  of  nerve  current,  or 
variations  of  external  or  internal  resistance,  a  clearer 
appreciation  of  the  laws  which  govern  the  nervous  system 
may  be  obtained. 

In  the  same  way  we  may  find  an  explanation  of  uni- 
polar, bipolar,  and  multipolar  cells.  The  storage-ganglion 
would  be  unipolar  and  the  condenser-ganglion  bipolar, 
while  a  cell  provided  with  two  or  more  sets  of  alternatingly 
conducting  and  insulating  materials  would  naturally  be 
multipolar.  Unfortunately  the  illustrations  to  be  found  in 
works  upon  Physiology  are  not  designed  to  show  the 
electrical  structure  of  nerve  cells  and  processes,  and 
therefore  the  difficulties  in  the  path  of  the  student  are 
great.  That  there  is  no  book  upon  Biology  or  Botany 
which  gives  any  information  upon  the  electrical  structure 
of  any  inhabitant  of  the  vegetable  kingdom  is  no  longer  to 
be  wondered  at  when  some  of  the  higher  forms  of  life  are 
little  understood.  And  yet,  once  the  eye  has  been  taught 
to  observe,  that  electrical  structure  is  so  clearly  evident  that 
the  most  remarkable  thing  about  it  is  the  obscurity  in  which 
it  has  remained. 

Some  further  light  is  thrown  upon  the  function  of  the 
storage-ganglia  by  the  electro-cardiograms  given  by  athletes 
after  strenuous  physical  effort  has  exhausted  their  reserves. 
Nature  has  to  generate  nerve  force  to  supply  the  immediate 
requirements  of  the  body,  and  as  part  of  this  is,  and  must 


202        STUDIES   IN  ELECTRO -PHYSIOLOGY  : 

be,  taken  up  by  the  storage-ganglia  to  replace  the  charge 
given  out  by  them,  the  process  of  recovery,  as  shown  by 
the  string  galvanometer,  is  slow.  The  hypothesis,  there- 
fore, that  the  ganglion  cells  receive  "  charge  "  and  not 
''  irritations  "  seems  to  be  tenable.  In  Thornton's  Human 
Physiology  we  are  told  that  by  a  nerve-centre  we  must 
understand  a  ganglion  cell,  or  group  of  cells,  capable  of 
receiving,  modifying,  and  discharging  nerve  impulses,  and 
thus  acting  for  the  performance  of  some  function.  As  I 
have  explained  it,  this  is  intelligible.  Reject  that  explana- 
tion and  no  one  law  remains  to  account  for  all  the 
phenomena.  There  can  only  be  one  law,  and  that  law 
applies  with  equal  force  to  both  the  animal  and  vegetable 
worlds.  Every  observed  phenomenon  must  be  in  harmony 
with  it,  if  the  observer  is  not  in  error. 

Turning  again  to  Thornton,  the  following  passage  is 
worth  quoting  :  "  Experimental  excitation  shows  that  the 
anterior  root  "  (of  a  spinal  nerve)  "  contains  efferent  fibres 
and  the  posterior  afferent  fibres.  .  .  .  Other  fibres  pass 
by  these  cells  and  do  not  appear  to  be  connected  with 
them.  What  their  nature  is  cannot  yet  be  stated."  All 
this  is  consistent  with  condenser-action,  and  may  be 
explained  by  it.  What  appears  to  be  required  is  that  the 
specialist  physiologist  should  collaborate  with  the  specialist 
electrician  in  the  study  of  the  human  nervous  system,  and 
I  think  this  will  have  to  be  done  if  appreciable  progress  is 
to  be  made  during  our  lifetime. 

"  Upon  the  object  of  autonomic  ganglia  I  can  find  nothing 
which  conflicts  with  the  views  I  hold.  ..."  Nature  has, 
as  it  were,  before  her  the  problem  of  supplying  with  nerves 
the  vast  mass  of  muscles  in  the  body,  and  the  space  at  her 
command  in  the  various  exits  from  the  cranium  and  spinal 
canal  does^  not  allow  of  more  than  a  comparatively  small 
outflow  from  the  central  nervous  system. 

"  The  difficulty  is  met  to  some  extent  by  the  branching 


ANIMAL   AND   VEGETABLE  208 

of  the  out-flowing  nerve-fibres,  and  in  the  case  of  the 
voluntary  muscles  this  appears  to  be  sufficient.  The 
most  striking  example  of  this  can  be  seen  in  the  electrical 
organ  of  the  malapterurus,  where  the  millions  of  its  sub- 
divisions on  each  side  of  the  body  are  all  supplied  by  the 
branches  of  a  single  axis -cylinder  process  originating  from 
a  single  giant  nerve-cell  in  the  brain. 

"  But  in  the  case  of  the  involuntary  muscular  tissue 
there  is  an  additional  means  of  distribution,  for  each  fibre 
that  leaves  the  central  nervous  system  arborises  around  a 
number  of  cells  in  the  autonomic  ganglia,  and  thus  the 
impulse  is  transferred  to  a  large  number  of  new  axis- 
cylinder  processes.  .  .  .  The  afferent  or  sensory  fibres  are 
much  less  numerous  than  those  which  are  efferent.  .  .  . 
Thus  in  the  splanchnic  and  hypogastric  nerves  about  one- 
tenth  of  the  fibres  are  found  to  be  sensory,  and  in  the 
pelvic  nerve  about  one-third  of  the  total  fibres  are  sen- 
sory."   (Halliburton,  1915.) 

UNIPOLAR   AND   BIPOLAR   NERVE   CELLS. 

Unipolar  cells,  as  I  have  stated,  are,  in  my  view,  storage 
cells,  and  appear  to  be  prominently  associated  with  the 
closed  circuits  of  the  sensory  nerves.  In  common  with 
other  nerve-cells  they  contain  at  least  one  conducting 
substance  in  organically  combined  iron  (Macallum),  and 
non-conducting  substances,  possibly  the  deep  and  super- 
ficial reticula  described  by  Golgi  and  regarded  by  J.  Turner 
as  investments  derived  from  neuroglia  cells.  However 
that  may  be,  I  am  constrained  to  the  opinion  that  in  all 
nerve-cells  we  have  a  form  or  forms  of  condenser  or  Leyden 
jar  ;  that  is  to  say,  they  may  consist  of  one  or  more  jars,  and 
that,  if  more  than  one,  these  elements  may  be  connected  in 
series  or  in  parallel,  for  the  regulation,  adjustment,  and 
distribution  of  tension. 


204      STUDIES  IN   ELECTRO -PHYSIOLOGY  : 

The  best  illustrations  I  have  been  able  to  find  are  given 
in  Schafer's  Essentials  of  Histology,  and  I  reproduce  them 
in  the  hope  that  the  apparently  electrical  structure  may 
stimulate  further  research  and  pave  the  way  to  their 
explanation  in  electrical  as  well  as  in  physiological  terms. 

Before  doing  so,  however,  we  may  usefully  remember 
that  "  in  the  ganglia  each  nerve -cell  has  a  nucleated  sheath 
which  is  continuous  with  the  neurilemma  of  the  nerve-fibre 
with  which  the  cell  is  connected ;  that  in  the  spinal 
ganglia  the  axis-cylinder  process  divides  into  two  within 
the  ganglion,  one  fibre  passing  to  the  nerve-centre  and 
the  other  towards  the  periphery  ;  while  in  the  sympathetic 
ganglia  the  nerve-cells  usualty  have  several  dendrons  and 
one  axon." 

Furthermore,  "  the  cells  of  ganglia  are  disposed  in 
aggregations  of  different  size,  separated  by  bundles  of  nerve- 
fibres  which  are  traversing  the  ganglion.  The  latter,  if 
large,  is  inclosed  by  an  investing  capsule  of  connective  tissue 
which  is  continuous  with  the  epineurium  and  perineurium 
of  the  entering  and  issuing  nerve- trunks."    (Schafer.) 

A  peculiarity  which  should  not  be  lost  sight  of  is  that 
in  the  spinal  ganglia  and  in  many  of  the  corresponding 
ganglia  on  the  roots  of  the  cranial  nerves  of  mammals  the 
only  issuing  process  is  the  axon,  and  when  this  divides  into 
two  the  branching  is  T-shaped  or  Y-shaped,  and  always 
occurs  at  a  node  of  Ranvier  ;  the  neuro-fibrils  of  the  central 
and  peripheral  branches  retaining  their  individuality  in 
the  common  trunk  and  being  traceable  into  a  neuro-fibril 
network  within  the  ceil  body. 

And  now,  having  collated  these  facts,  let  us  remember 
that  an  electrified  ball  exhibits  the  same  tension  on  every  part, 
and  see  how  this  physical  law  agrees  with  the  theory  of 
neuro- electrical  cell-action,  taking  into  consideration  that, 
while  every  cell  in  thie  body  may  be,  in  a  sense,  a  condenser, 
transmitting  neuro-electrical  impulses  in  various  directions 


ANIMAL  AND   VEGETABLE 


205 


and  with  varying  tension,  every  cell  is  not  of  the  same 
structure  or  designed  for  the  performance  of  the  same 
function.  We  must,  therefore,  examine  them  in  detail  and 
have  special  regard  to  their  formation,  so  far  as  it  has  been 
made  clear,  or  can  be  said  to  be  suggestive  to  the  electrician. 


Fig.  109. 

Unipolak  Cell  from  spinal  ganglion  of  rabbit,  a,  axon  ;  h,  circum- 
nuclear  zone,  poor  in  granules  ;  c,  capsule  ;  d,  network  within  nucleus  ; 
c,  nucleolus.     (After  Schafer.) 


Fig.  110. 

Bipolar  Cell  (ganglion)  of  lish  (Holmgren).  It  will  be  noticed  that 
the  medullary  sheath  is  continued  as  a  thin  layer  over  the  cell-body. 
(After  Schafer.) 


MULTIPOLAR    CELLS. 

So  far,  the  cells  appear  to  be  more  or  less  globular  in 
shape,  and  while  the  multipolar  cells  of  the  cerebral  cortex 
and  spinal  cord  appear  to  differ  materially,  as  a  whole, 
from  those  of  the  unipolar  and  bipolar  type,  they  must 
obey  the  law,  and  therefore  possess,  although  perhaps  in 
a  modified  form,  the  same  internal  arrangement  or 
arrangements  and  similar  absolute  capsular  insulation. 


206      STUDIES   IN  ELECTRO-PHYSIOLOGY: 

To  the  electrician  the  construction  of  a  multipolar  cell 
to  transmit  efferent  and  afferent  impulses  would  be  a 
comparatively   simple   matter.     Take  two   hollow  metal 

globes  or  ellipses  or  modifications 
.mreorylxvrf  o^   ^i^^er,   place   one  inside   the 

other  in  such  manner  that  there 
^^  "^  ^         is  an  air-space  or  insulating  layer 
\.7kncrC^l>e         between  them,  and  drill  a  hole  in 
the   outer   globe   to   receive   an 
Fig.  Ill .  insulated  wire,  which  would  make 

metallic  contact  with  the  inner 
globe  (Fig.  111).  The  next  step  would  be  to  solder  a 
number  of  insulated  wires  to  the  outer  globe,  and  to  then 
provide  absolute  insulation  for  the  whole  by  coating  the 
outer  globe  with,  say,  gutta-percha  solution  or  Chatterton's 
compound. 

Now,  in  a  Ley  den  jar  the  inner  and  outer  coatings  are 
metallic,  the  glass  walls  of  the  jar  form  the  dielectric 
substance,  and  discharge  is  prevented  by  the  resistance 
interposed'by  air  intervening  between  the  outer  coating  and 
the  earth.  In  the  human  body  all  the  nerves  are  to  earth, 
through  the  air,  and  the  resistance  of  that  intervening 
stratum  of  air  is  sufficiently  great  to  prevent  discharge, 
under  normal  conditions  of  charge,  taking  place  prematurely. 
When,  however,  a  motor  or  secretory  nerve  receives  an 
efferent  impulse,  or  it  may  be  impulses,  the  added  tension 
is  just  enough  to  bridge  the  spark  gap,  as  it  were,  and  so  to 
permit  of  a  discharge  or  partial  discharge. 

It  will  be  seen,  however,  that  the  surface  area  and 
therefore  the  tension  of  the  two  globes,  as  sketched  in 
Fig. Ill,  is  not  the  same,  and  that  if  the  impulse  conveyed 
by  the  axon  were  an  efferent  impulse  all  the  wires  connected 
to  the  outer  globe  would  transmit  lower-tension  afferent 
impulses,  in  which  case  the  cell  would  not  be  multipolar. 
But  in  the  majority  at  least  of  these  cells  there  are 


ANIMAL  AND   VEGETABLE  207 

branch  circuits,  collaterals,  or  dendrons  (corresponding  to 
our  wires  of  the  outer  globe)  which  terminate  in  arborisa- 
tions or  end- organs,  connecting,  interlacing,  or  inter- 
mingling with  other  nerve-cells,  of  which  they  are  anato- 
mically independent.  These  other  cells  and  arborisations 
act,  as  I  have  endeavoured  to  show,  as  condensers  in 
changing  the  sign  of  current  or  impulse,  and,  as  I  have 
suggested,  any  variation  of  tension  may  be  brought  about 
by  varying  the  area  of  the  condenser-plates,  discs,  or 
points,  or  conducting  cell  areas. 

In  the  typical  multipolar  cells  of  the  spinal  cord,  as 
shown  by  Max  Schultze,  only  one  process  becomes  the 
axis-cylinder  of  a  nerve-fibre,  the  others  breaking  up  into 
arborisations  oi  fibrils  which  can  be  traced  into  the  axon 
and  the  other  branches  of  the  cell.  "  Between  the  fibrils 
the  protoplasm  of  the  cell  contains  a  number  of  angular  or 
spindle-shaped  masses  .  .  .  known  as  NissVs  granules  " 
(seep.  189).  "  These  nerve-cdls  often  contain  . .  .  granules 
of  pigment,  usually  yellow,  the  nature  of  which  has  not 
been  determined."  As  a  matter  of  possibility,  the  yellow 
pigment  may  be  an  insulating  substance  of  the  nature  of 
elastin,  but  as  to  this  I  am  not,  in  the  absence  of  any 
definite  information  as  to  its  chemical  composition,  able  to 
offer  an  opinion. 

We  may  now  compare  a  multipolar  ganglion  cell  as 
illustrated  physiologically  with  the  artificial  contrivance 
before  mentioned.    (Figs.  112,  113.) 

Supposing  an  efferent  impulse  to  be  conveyed  to  the 
inner  globe,  as  shown  in  the  electrical  diagram,  all  the 
discharge  impulses  would  be  afferent,  and,  as  I  before 
remarked,  the  cell  would  not  be  multipolar.  A  condenser 
of  suitable  capacity  inserted  between  any  one  or  more  of 
the  terminals  c,  d,  e,  g,  h,  i,  j,  k,  would  retransform  the 
impulse  from  afferent  to  efferent,  and  either  raise  or  further 
lower   the  tension   in   accordance   with  its   surface  area, 


208       STUDIES  IN  ELECTRO-PHYSIOLOGY 


Physiological. 


Electrical. 


^u1hreiafBJ!& 


hi^  i&■^bk■^t 


ff  il'kroud/thi^  rssboAic^ 


Fig.  112.  Fig.  113.  (4/"/er  Schdfer.) 

Physiological.  A,  large  pyramidal  cell  of  cerebral  cortex,  human.  NissI 
method  (Cajal).  a,  axon  ;  6,  ceil  body  ;  c,  apical  dendron  ;  d,  placed  betAveen 
two  of  the  basal  dendrons,  points  to  the  nucleus  of  a  neuroglia  cell ;  diagram 
reversed.  Seven  other  branches,  presumably  dendrons,  or  collaterals,  are  shown, 
and  these  must  interlace,  by  means  of  their  arborisations,  \\'ith  other  cells. 

Electrical.  B,  battery ;  a,  axon  or  line-wire  ;  b,  insulating  cover  or 
capsule  ;   c,  d,  e,  g,  h,  i,  j,  k,  branches  from  outer  globe. 


while,  if  it  was  desired  to  retain  an  afferent  impulse  at  any 
point,  no  condenser  would  be  inserted  at  that  point. 
Physiologically,  of  course,  the  dendrons  would  inductively 
connect  with  neighbouring  cells  by  means  of  their  arborisa- 
tions ;  electrically  the  condensers,  when  inserted,  would  be 
connected  more  or  less  as  shown  in  Fig.  114. 

It  is  quite  evident,  however,  that  this  explanation  of 
the  functioning  of  a  multipolar  cell  is  insufficient.  Suppos- 
ing the  inner  and  outer  globes  to  act  as  a  Leyden  jar,  all 
the  impulses,  efferent  and  afferent,  would  be  conveyed 
simultaneously  with  each  discharge,  and  while  Nature  does 
not  waste  any  impulse  but  utilises  it  in  the  motor,  secretory, 


ANIMAL  AND  VEGETABLE 


209 


and  some  sensory  paths,  it  seems  to  me  improbable  that 
action  takes  place  in  the  manner  I  have  described.  Even 
if  the  branch  circuits  or  collaterals,  with  their  inductive 
effect  upon  cells  contiguous  to  them,  were  of  different 
resistance  and  the  cells  of  varying  capacity,  the  impulses 
would  still  be  simultaneous,  though  varied  as  to  tension. 
We  must  therefore,  I  think,  come  to  the  conclusion  that 


SfAro'Al^A  n^ 


to  earth  thm'fu^ree 


Fig.  114. 
Diagram,  showing  how  an  artificial  multipolar  cell  circuit  might  be 
arranged  to  give  any  number  of  efferent  and  afferent  impulses. 

instead  of  a  multipolar  ganglion  cell  being  made  up  of  one 
Ley  den  jar  with  multiple  connections,  it  is  made  up  of 
many  such  jars  or  rings,  and  that  the  axis-cylinder  process 
divides,  not  into  two,  but  into  as  many  independent  or, 
in  other  words,  insulated  fibres  or  fibrils  as  there  are 
collaterals,  and  that  each  of  these  fibrils  leads  to  a  separate, 
though  perhaps  not  anatomically  distinct,  condenser  or 
jar,  and,  inductively,  through  that  jar  to  the  dendron 
designed  to  convey  a  specific  impulse,  efferent  or  afferent. 


210      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

I  am  encouraged  in  this  opinion  by  a  careful  study  of 
the  structure  of  unipolar  cells  and  by  other  considerations. 
To  my  mind  it  would  appear  that  the  structure  of  even  the 
unipolar  cell  is  not  simple  but  complex.  It  seems  to  be 
circular  in  form  throughout — ^to  be,  in  fact,  a  series  of  rings  ; 
and  while  the  microscope  has  not,  so  far,  given  us  the 
needful  detail,  it  does  not  call  for  an  undue  stretch  of  the 
imagination  to  believe  that  it  may,  possibly,  be  composed  of 
a  series  of  Ley  den  jars  ;  that  is  to  say,  circular  layers  of 
conducting  substances  with  non-conducting  substances 
between  them,  and  that  such  layers,  like  the  sarcomeres, 
are  insulated  from  each  other  and  are  in  connection  with 
certain  assigned  nerve-fibres  or  fibrils.  In  such  case  we 
can  conceive  in  a  multipolar  cell  the  impulse  being  given, 
as  a  whole,  from  a  principal  central  system,  or,  individually> 
to  any  dendron  or  branch  circuit. 

Since  writing  the  foregoing  my  attention  has  been 
drawn  to  an  illustration  in  Haeckel's  Evolution  of  Man 
(taken  from  Max  Schultze)  of  a  multipolar  cell  from  the 
brain  of  an  electric  fish,  and  as  it  seems  to  confirm  my 
theory  I  reproduce  it.     (Fig.  115.) 

Reverting  to  the  typical  multipolar  cell  of  the  spinal 
cord,  and  at  the  risk  of  repetition,  I  must  remind  my 
readers  that  the  axis -cylinder  process  itself  invariably 
gives  off  side  branches  or  collaterals,  which  pass  into  the 
adjacent  nerve-tissue.  "  The  axis-cylinder  then  acquires 
the  sheaths,  and  thus  is  converted  into  a  nerve-fibre. 
This  nerve-fibre  sometimes,  as  in  the  nerve-centres  after  a 
more  or  less  extended  course,  breaks  up  into  a  terminal 
arborescence  enveloping  other  nerve-cells  ;  the  collaterals 
also  terminate  in  a  similar  way  ...  all  ultimately  ter- 
minate in  an  arborescence  of  fibrils  in  various  end-organs 
(end-plates,  muscle-spindles,  etc.)." 

Furthermore,  "  each  nerve-unit  (cell,  plus  branches  of 
both  kinds)  is  anatomically  independent  of  every  other 


ANIMAL  AND   VEGETABLE  211 

nerve-unit.  There  is  no  true  anastomosis  of  the  branches 
from  one  nerve-cell  with  those  of  another,  and  nerve 
impulses  are  transmitted  from  one  nerve-unit  to  another, 


Fig.  115. 
A  Large  Branching  Nerve-Cell,  from  the  brain  of  an  electric  fish 
(Torpedo),  magnified  600  times.  In  the  middle  of  the  cell  is  the  large 
transparent  round  nucleus,  one  nucleolus,  and,  within  the  latter  again,  a 
nucleolinus.  The  protoplasm  of  the  cell  is  spUt  into  innumerable  fine 
threads  (or  fibrils),  which  are  embedded  in  intercellular  matter,  and  are 
prolonged  into  the  branching  processes  of  the  cell  (&).  One  branch  (a) 
passes  into  a  nerve-fibre.    {From  Max  SchuUze.) 


through  contiguous  but  not  through  continuous  structures." 
(Halliburton.) 


212       STUDIES   IN  ELECTRO-PHYSIOLOGY: 

The  following  illustration  is  given  to   explain  reflex 
action  : — 


Fig.  116. — Reflex  Action.    (After  Halliburton.) 

Excitation  occurs,  we  will  say,  at  a  sensory  surface  S, 
and  the  impulse  is  transmitted  by  the  sensory  nerve-fibre 
to  the  central  nervous  system.  "  This  fibre  does  not 
become  anatomically  connected  to  any  of  the  cells  of  the 
central  nervous  system.  The  only  cell-body  in  actual 
continuity  with  the  sensory  nerve-fibre  is  the  one  in  the 
spinal  ganglion  (G) "  (a  storage  cell).  "  On  entering  the 
spinal  cord  the  main  fibre  conveys  impulses  upwards  which 
ultimately  reach  the  brain,  but  in  the  spinal  cord  it  gives 
off  fine  side  branches  or  collaterals  which  terminate  by 
arborising  around  one  or  more  cell -bodies  and  their  den- 
drons  ;  these  cells  are  small  ones  situated  in  the  posterior 
cornu  of  the  spinal  grey  matter  ;  one  only  (PCC)  is  shown 
in  the  diagram.  The  short  axon  of  this  cell  similarly  ter- 
minates by  a  synaptic  junction  with  one  or  more  of  the 
large  multipolar  cells  of  the  anterior  cornu  of  the  spinal 
grey  matter  ;  one  of  these  shown  in  the  figure  is  labelled 
ACC.  This  motor  cell  is  thus  stirred  up  to  action  and 
sends  an  impulse  by  its  axon  to  the  muscular  fibres  it 
supplies."    (Halliburton.) 

I   may   remark,    in   parenthesis,    that   we   have   here 
evidence  of  condenser-action,  of  cells  changing  the  sign  of 


[^ANIMAL  AND   VEGETABLE  218 

current  and  transforming,  in  a  shunt-circuit,  an  afferent 
to  an  efferent  impulse.  The  correct  number  of  cells  is  not 
shown,  but  any  even  number  between  G  and  ACC  or  any 
uneven  number  between  the  sensory  nerve-fibre  and  the 
motor  fibre  would  do  it. 

Halliburton  avers  that  :  "  The  synaptic  junctions  are 
naturally  the  places  which  the  impulse  has  the  greatest 
difficulty  in  traversing  ;  and  some  observers  believe  that  at  the 
points  of  contact  there  is  a  kind  of  undifferentiated  interstitial 
protoplasm  which  the  impulse  has  to  get  through.^'  * 

Suppose  there  to  be  many  thousands  of  such  synaptic 
junctions,  or,  electrically  speaking,  many  thousands  of 
condensers  of  varying  capacity,  concentrated  over  a  length 
of,  say,  three  feet,  and  further  suppose  them  to  be  ulti- 
mately connected  to  a  copper  wire  of  three  feet  in  length 
to  earth  through  a  high  resistance  at  its  further  end.  Let 
the  condenser -length  be  from  A  to  B  and  the  wire-length 
from  B  to  C.  Would  the  velocity  of  a  current  of  electricity 
sent  from  A  to  B  be  the  same  as  from  B  to  C  ? 
Obviously  it  would  not,  could  not,  be. 

Going  back,  after  these  interpolations,  to  our  diagram 
of  reflex  action,  the  electrical  impulse,  due  to  alteration  of 
resistance  at  S  caused  by,  for  instance,  a  rise  or  fall  of 
temperature,  by  pressure  upon  the  skin,  etc.,  would  be 
afferent.  Upon  reaching  the  storage  cell,  G,  it  would  be 
affected  or  unaffected  by  difference  or  non-difference  of 
potential  between  sensory  nerve-fibre  and  cell.  If  the  cell 
held  its  normal  charge,  the  impulse  would  pass  unaltered 
(by  that  cell)  on  its  path  to  the  brain.  If,  however,  the 
potential  of  the  cell  was  higher  than  that  of  the  fibre,  the 
impulse  would  be  increased  or  accelerated,  and  vice  versa. 
At  the  point  PCC,  the  cell  there  would  be  in  an  inductive 

*  The  italics  are  my  own  and  are  intended  to  suggest  a  reason,  one 
reason,  for  the  comparatively  very  low  velocity  of  the  nerve-current  as 
compared  with  that  of  electricity  along  a  wire  or  cable. 


214        STUDIES  IN   ELECTRO-PHYSIOLOGY 

shunt-circuit,  and  would  transform  some  portion  of  the 
afferent  impulse  to  an  efferent  one,  should  no  other  cell  be 
between  it  and  the  muscular  fibre.  The  multipolar  cell,  ACC, 
being  interposed,  it  follows  that  one  cell  between  the  sensory 
nerve  and  themuscular  nerve-fibre  is  omitted  in  the  diagram. 

"  For  a  reflex  action,"  remarks  Halliburton,  "  three 
things  are  necessary  :  (1)  an  afferent  nerve,  (2)  a  nerve- 
centre  consisting  of  nerve-cells  to  receive  the  afferent 
impulse  and  send  out  the  efferent  impulse,  and  (3)  an 
efferent  nerve  along  which  the  efferent  impulse  may 
travel." — Verb.  sap. 

I  have  said  that  in  my  view  unipolar  cells  are  of  the 
storage  type  and  appear  to  be  prominently  associated  with 


Fig,  117.  - 

Shows  on  the  left  the  motor  nuclei  and  efferent  fibres,  except  those  of 
the  fourth  nerve,  and  on  the  right  side  the  afferent  fibres.    {After  Schdfer.) 

sensory  nerve-fibres  ;  their  function,  mainly  if  not  entirely, 
being  to  maintain  equilibrium  in  a  closed-circuit  system. 

In  this  connection  there  are  at  least  two  diagrams  in 
Schafer's  Essentials  of  Histology  which  support  my  view> 


ANIMAL  AND   VEGETABLE 


215 


and  I  am  of  opinion  that  if  we  had  a  complete  plan  of  the 
nervous  system,  showing  the  whole  of  the  efferent  and 
afferent  nerve-fibres  and  all  the  intervening  cells,  with  their 
arborisations,  so  that  the  different  circuits  could  be  traced, 
my  contention  as  to  condenser-action  in  the  body  would  be 
more  than  amply  justified. 

The  first  of  the  diagrams  to  which  I  have  referred  is 
given  in  the  chapter  upon  the  Medulla  Oblongata,  and  is 
intended  to  illustrate  the  origin  and  relations  of  the  root- 
fibres  of  the  cranial  nerves  (Fig.  117). 

There  is  a  further  diagram  of  the  efferent  fibres  only, 
but  no  unipolar  or  storage  cell  appears. 

The  second  diagram  to  which  I  have  alluded  is  given  in 
the  chapter  upon  the  Pons  Varolii,  and  is  a  plan  of  the 
origin  of  the  fifth  nerve  : — 


f^   ^  cv 


Fig.  118. 
G,  Gasserion  ganglion  ;  a,  6,  c,  three  divisions  of  the  nerve  ;  m'nv, 
superior  motor  nucleus  ;  mnv,  principal  motor  nucleus  ;  psno,  principal 
sensory  nucleus  ;  asnv,  dnsv,  descending  sensory  nucleus  ;  dsv,  descending 
root ;  cv,  c'v,  central  sensory  tracts  composed  of  fibres  emanating  from 
the  sensory  nuclei ;   r,  plane  of  the  raphe.     {After  Schdfer.) 


216      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

The  fifth  or  trigeminal  nerve,  it  is  scarcely  necessary  to 
remark,  emerges  at  the  side  of  the  pons  in  two  roots,  a 
small  motor  and  a  large  sensory,  and  it  is  only  in  connection 
with  the  sensory  nerve  that  we  find  the  spherical  unipolar 
cells  associated.  The  motor  root,  as  one  might  expect,  is 
provided  with  numerous  multipolar  cells,  so  that  it  cannot 
be  said  to  be  entirely  distinct  from  the  larger  posterior 
sensory  root  with  which  it  emerges,  inasmuch  as  any 
branch  of  it  can  be  made  afferent,  although  not  sensory  in 
the  sense  of  a  closed  circuit,  by  the  insertion  of  a  bipolar 
cell  between  a  motor  nerve-fibre  and  a  branch. 

Before  concluding  this  study  I  should  like  my  readers 
to  take  careful  note  that  in  the  course  of  voluntary  motor 
fibres,  before  they  pass  into  the  anterior  root  (spinal  cord) 
they  always  first  form  connections  with  the  multipolar 
nerve-cells  of  the  anterior  cornu,  which,  in  fact,  are  intro- 
duced into  the  course  of  the  conducting-paths  ;  but,  in 
their  passage  through  the  brain,  the  paths  for  direct  motor 
impulses  are  not  interrupted  anywhere  in  their  course  by 
ganglion  cells,  not  even  in  the  corpus  striatum  or  pons. 
They  pass  in  a  direct  uninterrupted  course. 


ANIMAL  AND   VEGETABLE  217 


Chapter  XVI 
THE  EYE   AND  THE  EAR 

The   Eye 

If  I  shrink  from  giving  a  detailed  description  of  the 
manner  in  which  I  believe  these  two  organs  of  special  sense 
operate,  it  is  not  because  the  task  is  beyond  me,  but  because, 
owing  to  my  limited  knowledge  of  histology  and  the 
paucity  of  information — as  regards  the  neuro-electrical 
ramifications  of  the  circuits — ^for  my  enlightenment,  I 
grudge  the  time  that  would  have  to  be  spent  in  further 
research ;  whereas  a  physiologist  who  could  bring  himself 
to  ponder  the  matter  from  a  purely  electrical,  or  rather 
from  a  purely  telegraphic  and  telephonic  point  of  view, 
would,  I  have  no  doubt,  be  able  to  do  the  subject  greater 
justice. 

At  the  same  time,  it  is  incumbent  upon  me  to  put  upon 
record  my  opinion  that  the  eye  is  strongly  suggestive  of  a 
compound  selenium-cell  transmitting  apparatus,  and  that 
the  ear  does  not  differ  in  any  essential  respect  from  a 
telephone  system,  the  outer  ear  being  the  receiver,  the 
middle  ear  the  microphone,  and  the  auditory  nerve  the 
line  wire  or  wires  to  the  brain. 

The  element  called  selenium  is  not  very  well  known 
outside  the  precincts  of  the  laboratory.  It  was  discovered 
in  the  year  1817  in  the  refuse  of  a  sulphuric  acid 
manufactory  in  Sweden  by  Berzelius,  and  is  obtained  in 
two  forms,  one  of  which  is  soluble  in  carbon  disulphide, 
the  other  being  insoluble  in  the  same  medium.     The  first 


218      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

is  of  a  reddish-yellow  colour,  conducting  heat  badly  and 
electricity  not  at  all,  while  the  other  variety — known  as 
black  or  metallic  selenium — conducts  heat,  and  under  certain 
conditions  wUl  form  a  good  conductor  of  electricity.  It  is 
with  the  latter  only  that  we  are  concerned. 

In  1873  Mr.  Wiiloughby  Smith,  then  electrician-in-chief 
to  the  Telegraph  Construction  and  Maintenance  Company, 
discovered  that  this  substance  had  a  peculiar  property  in 
that  its  electrical  resistance  varied  with  the  amount  of  light 
to  which  it  v/as  subjected  ;  the  difference  in  these  varia- 
tions being  very  marked,  and  in  the  inverse  ratio  to  the 
degree  of  light.  Later  on  Dr.  Siemens,  Professor  Adams, 
the  Earl  of  Rosse,  and  other  scientific  men  took  up  the 
subject,  but  nothing  practical  was  done  until  Professor 
Graham  Bell,  in  association  with  Mr.  Sumner  Tainter, 
produced  the  photophone,  an  instrument  in  which  light 
was  utilised  for  the  transmission  of  sound. 

Of  more  interest  to  us,  however,  is  the  "  Selenium 
eye  "  of  Dr.  Siemens.  It  was  in  reality  an  artificial  human 
eye,  with  a  lens  in  front,  and  lids  to  close  when  it  was 
weary  ;  for,  curious  as  it  may  seem,  it,  like  its  perfect 
prototype,  became  tired  when  exposed  for  a  prolonged 
period  to  bright  light. 

The  lens  caused  any  light  to  which  the  "  eye  "  was 
subjected  to  be  concentrated  in  the  interior  of  the  eyeball, 
and  at  this  spot  a  selenium  grating  was  placed.  This  was 
composed  of  two  fine  wires  running  together  in  zigzag 
fashion,  but  not  making  actual  contact.  Upon  these  was 
placed  a  melted  drop  of  selenium,  and  the  ends  of  the  wires 
were  joined  up  with  a  galvanometer  and  battery.  When 
the  "  eye  "  had  been  closed  and  at  rest  for  some  little  time, 
it  was  found  to  be  sensitive  to  the  faintest  gleam  of  light, 
but  after  long  exposure  to  bright  light  the  lids  closed  for 
a  long  time  before  it  became  again  sensitive  to  feeble  rays. 

Since  then  much  experimental  work  has  been  done,  and 


ANIMAL  AND   VEGETABLE  219 

inventions  of  scientific  interest  but  no  great  commercial 
value  have  resulted. 

One  of  the  most  successful  attempts — the  in- 
vention of  a  Pole  named  Szczepanik — to  transmit  pictures 
to  a  distance  by  the  agency  of  selenium  was  described  in 
Pearson's  Magazine  of  October,  1899,  by  Mr.  Cleveland 
Moffett.  It  was  called  the  "  Telectroscope,"  and  was 
founded  upon  the  fact  that  any  vision  or  image  produced 
upon  the  retina  is  only  the  blending  together  of  an  infinite 
number  of  points  projected  separately  from  the  object  and 
seen  by  separate  rays  of  light.  Some  of  these  come  a 
fraction  of  a  second  later  than  others,  but  if  the  intervals 
between  them  be  short  enough  persistence  of  vision  will 
have  the  effect  of  bringing  them  together  and  forming  a 
complete  picture. 

From  the  article  in  question  I  gather  that  Szczepanik 
devised  a  way  of  separating  any  image  formed  by  an 
ordinary  photographic  lens  into  its  component  luminous 
points,  of  transmitting  these  points  separately,  but  with 
enormous  rapidity,  over  wires,  and  letting  the  eye  recon- 
stitute them  at  the  other  end  into  the  original  picture. 

Selenium,  it  may  be  said,  possesses  the  peculiar  property 
of  transforming  waves  of  light  into  waves  of  electricity, 
so  that  if  rays  of  light  are  thrown  upon  a  selenium  disc 
to  which  insulated  wires  are  connected,  it  will  be  found  that 
currents  are  set  up  in  the  wires,  and  moreover  that  rays  of 
light  differing  in  colour  and  intensity  give  rise  to  currents 
which  also  differ  in  intensity  ;  each  particular  ray  having 
its  corresponding  current,  and  no  two  of  them  being  exactly 
alike. 

Szczepanik 's  transmitting  apparatus  consisted  of  a  box 
with  a  camera  front  and  a  photographic  lens  for  focussing 
an  image  outside  the  box  upon  two  vibrating  mirrors, 
designed  to  resolve  the  image  into  points  and  project  these 
upon  a  selenium  disc  connected  by  wires  with  the  receiving 


220      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

apparatus.  The  transmitting  wires  terminated  in  two 
vibrating  metal  plates,  contained  in  another  enclosed  box 
with  a  camera  front,  and  these  plates,  by  an  ingenious 
method  of  lighting,  allowed  a  changing  band  of  light,  as 
thin  as  a  hair,  to  pass  between  them.  This  was  broken 
up  in  turn  by  two  other  vibrating  mirrors  and  projected 
upon  a  ground-glass  plate,  upon  which  the  transmitted 
image  appeared. 

The  inventor  solved  the  problem  of  the  conveyance  of 
colour  by  passing  the  rays  of  light  received  by  the  lens  in 
the  transmitter  and  from  the  vibrating  metal  plates  of  the 
receiver  through  a  prism,  each  ray  being  deflected  more  or 
less  and  each  having  an  individual  deflection  ;  a  violet  ray 
being  deflected  more  than  a  yellow  ray,  and  a  red  ray  less 
than  a  green  one,  and  so  on. 

With  the  technical  details  of  the  Telestroscope  we  need 
have  no  further  concern.  Its  interest,  to  me,  lies  not  in 
the  mechanical  details — they  were  necessitated  by  the  fact 
of  there  being  only  one  selenium  disc  in  the  transmitting 
apparatus — but  in  certain  curious  points  of  resemblance 
to  the  human  eye. 

If,  instead  of  one  transmitting  disc  and  two  connecting 
wires,  an  infinite  number  of  such  discs  and  wires  could  have 
been  employed,  there  would  have  been  no  occasion  for  the 
vibrating  mirrors,  for  the  reason  that  the  "  points " 
projected  separately  from  the  object  would  be  received 
upon  a  large  number  of  discs  and  conveyed  to  the  brain 
by  a  large  number  of  wires  or  nerve-fibres.  The  number 
of  fibres  in  the  optic  nerve  is  said  to  be  upwards  of  500,000, 
while  the  number  of  cones  in  the  rod  and  cone  layer  of  the 
eye  of  man — the  nerve- epithelium  of  the  retina — has  been 
estimated  at  3,000,000. 

It  does  not  follow  that  these  discs  and  wires  are  as 
multitudinous  as  the  points  of  light  which  in  their  entirety 
form  a  picture  or  an  image.     It  is  because  they  are  not  so, 


ANIMAL   AND   VEGETABLE 


221 


I  take  it,  that  there  is  such  a  thing  as  memory  of  the  eye, 
or  persistence  of  vision. 

Comparing  the  lens  of  the  eye  with  that  of  a  camera,  the 
iris  is  the  diaphragm  to  regulate  the  aperture,  and  the  rays 
or  points  of  light  admitted  by  the  lens  are  thrown,  although 
not  directly,  upon  a  layer  of  pigment  cells  which  form 
the  outer  or  choroidal  surface  of  the  retina. 

It  should  also  be  noted  that  posteriorly  to  the  iris  is  a 
layer  of  pigment  cells,  a  continuation  forwards  of  the 
pigment  layer  of  the  retina. 


Fig.  119. — Pigmented  Epithelium  of  the  Human  Retina.  (Mam 
Schultze.) 

a,  cells  seen  from  the  outer  surface  with  clear  lines  of  intercellular 
substance  between  ;  b,  two  cells  seen  in  profile  with  fine  offsets  extending 
inwards  ;   c,  a  cell  still  in  connection  with  the  outer  ends  of  the  rods. 


In  colour  these  pigment  cells  appear  to  be  dark  brown, 
and,  like  the  macula  lutea,  apart  from  the  fovea  centralis, 
non-actinic. 

It  will  be  seen,  from  b  and  c,  that  fine  offsets  or  nerve- 
fibres  extend  inwards  from  these  cells,  and,  presumably, 
either  make  connection  with  or  influence  the  rods  and 
cones  in  their  immediate  vicinity  ;    these  rods  and  cones 


222      STUDIES   IN  ELECTRO-PHYSIOLOGY: 

connecting  by  means  of  various  nerve  processes  and  gan- 
glionic cells  with  the  brain. 

"  At  the  fovea  each  cone  is  connected  to  a  separate 
chain  of  neurons,  whereas  in  other  regions  the  rods  and 
cones  are  connected  in  groups  to  these  chains.  ...  At 
the  exit  of  the  optic  nerve  the  only  structures  present  are 
nerve-fibres.  .  .  .  The  nerve-cells  in  the  retina  remind  us 
that  the  optic,  like  the  olfactory  nerve,  is  not  a  mere  nerve 
but  an  outgrowth  of  the  brain."    (Halliburton.) 

The  clearest,  if  not  the  most  comprehensive,  exposition 
of  the  structure  and  functioning  of  the  eye,  so  far  as  my 
reading  goes,  is  contained  in  Thornton's  Human  Physiology. 
Briefly  summarising  this,  I  learn  that  the  outermost  layer 
of  the  retina  next  to  the  choroid  consists  of  a  single  stratum 
of  hexagonal  epithelium  containing  black — but,  according 
to  Schafer,  dark  brown — ^pigment.  They  are  present  in 
all  parts  of  the  retina,  except  at  the  entrance  of  the  optic 
nerve.  The  outer  surface  of  the  cells  is  smooth  and  flat, 
but  the  inner  part  is  prolonged  into  fine  processes  which 
extend  between  the  rods.  About  7,000  cones  are  said  to 
exist  in  the  fovea.  Near  the  macula  lutea  the  retina 
contains  one  cone  to  four  rods  ;  midway  to  its  termination 
at  the  ora  serrata  one  cone  to  twenty -four  rods  ;  at  the 
peripheral  part  rods  only. 

Visual  impulses  begin  in  the  rods  and  cones  on  the  outer 
side  of  the  retina,  after  the  rays  of  light  have  passed 
through  most  of  the  retinal  layers,  and  the  processes 
started  in  these  sensory  epithelial  cells  of  the  retina  pass 
back  to  the  layer  of  fibres  on  the  inner  surface  of  the  retina 
and  thence  by  the  optic  nerve  to  the  brain. 

We  know  that  the  retinal  vessels  are  distributed  in  the 
inner  layers  (nerve-fibres  and  ganglionic  cells)  of  the 
retina,  and  the  shadows  cast  behind  them  must  be  per- 
ceived by  something  posterior  to  those  vessels.  This  is  a  clear 
proof,  it  is  said,  that  the  external  layers  of  the  retina  nearest 


ANIMAL  AND   VEGETABLE  228 

the  choroid,  that  is,  the  rods  and  cones,  are  the  elements 
in  which  the  visual  impressions  begin. 

"  It  thus  appears  that  the  real  end-organs  of  vision, 
the  rods  and  cones,  must  be  in  some  way  connected  func- 
tionally, if  not  structurally,  with  the  nerve  filaments  that 
pass  to  the  optic  nerve,  and  it  is  evident  that  these  rods 
and  cones,  being  backwards  from  the  light  towards  the 
sclerotic,  must  receive  the  light  waves  after  they  have 
passed  through  the  internal  layers  of  the  retina,  except  at 
the  fovea,  where,  all  the  other  layers  having  thinned  off, 
the  basal  fibres  of  the  cones  themselves  are  directly  exposed 
to  the  light  waves."   (Thornton.) 

Before  we  accept  the  above  conclusions  as  final  it  will 
be  well  to  ponder  the  matter  carefully. 

There  are  several  points  which  call  for  consideration. 
Cones  are  absent  in  some  animals  and  rods  in  others. 
Light  produces  changes  in  pigment,  but  while  the  outer 
limbs  of  the  rods  are  tinged  with  a  pigment  termed 
*'  visual  purple,"  derived  from  the  pigment  cells  of  the 
outer  layer  of  the  retina,  it  can  hardly  be  essential  to  vision, 
as  it  is  "  absent  from  the  cones  of  the  fovea  and  entirely 
wanting  in  some  animals  that  see  well." 

I  am  not  going  to  suggest  that  the  epithelial  pigment 
cells  of  the  retina  contain  selenium,  but  I  do  suggest  that 
they  are  composed  of  or  contain  some  substance  which 
has  the  property  of  transforming  waves  of  light  into  waves 
of  neuro-electricity,  possibly  by  causing  enormously  rapid 
alterations  of  resistance  in  the  sensory  nerve- circuits 
connected  functionally,  if  not  structurally,  with  the  cells^ 

"  We  do  not  know,"  says  Thornton,  "  how  the  undula. 
tions  of  light  become  converted  into  nervous  impulses  that 
give  rise  to  visual  sensations." 

The  three  following  diagrams  (Figs.  120,  121,  122)  may 
with  advantage  be  considered  in  their  relation  to  the  known 
optical  law   that    "  ordinary  light    consists  of  vibrations 


224      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

taking  place  always  in  planes  at  right  angles  to  the 
direction  of  the  ray,  but  in  all  directions  in  those  planes. 
That  is,  if  the  ray  travels  along  the  axle  of  a  wheel,  the 
vibrations  composing  it  are  all  in  the  plane  of  the  wheel, 
but  are  executed  along  any  or  all  of  the  spokes."  (Gordon's 
Electricity  and  Magnetism.) 

Rays  of  light,  entering  at  the  lens,  would,  if  the  lens 
were  a  fixed  object,  approximate  to  the  axle,  and  the  rods 
and  cones  to  the  spokes  of  the  wheel.  But  the  lens  is  not 
a  fixed  object,  as  in  a  camera.  It  not  only  receives  rays 
of  light  from  above,  below,  and  each  side,  but  continually 
shifts  its  angle  of  reception  of  such  rays  by  movement  of 
the  eye. 


Fig.  120, 
Diagram  of  a  section  through  the  (right)  human  eye  passing  horizontally 
neariy  through  the  middle,     a,  b,  equator  ;   y,  optic  axis.    {After  Schafer.) 

The  pigmented  cells  of  the  outer  or  choroidal  surface 
are  not  shown  in  Fig.  121,  but  are  illustrated  by  Schultze 
in  a  diagrammatic  section  of  the  human  retina  (Fig.  122). 


ANIMAL  AND   VEGETABLE 


225 


Fig.  121. 

Vertical  section  through  the  Macula  Lutea  and  Fovea  CentraKg; 
diagrammatic,     (Thornton,  after  M.  Schulize.) 

1,  nerve  layer  ;  2,  ganglionic  layer  ;  3,  inner  molecular,  4,  inner  nuclear, 
and  5,  outer  molecular  layers  ;  6,  outer  nuclear  layer,  the  inner  part  with 
only  cone  fibres  forming  the  so-called  external  fibrous  layer  ;  7,  cones  and 
rods. 


Outer  cr  CAcrouici! Sur,^acS 

8  Lauero^R^mint  celh 

7.  Z.aifcrofrods  Scones 

O  Outer  /lucLazr  l.auj&r 

J  Outer  3uruzpse 

■4  In  ner nuclear  or  bipdarLaua 


O  I nri&r  /Suna-ps* 

£ .  Zcii^traJ'ovUc  neroe-c^fh 
/  I.a.tjerip/'cpiic  neroeyzires 

}A7em6rariaiimii<2ns  inferna 


//inerSurJaxA 


Fig.  122. — Diagrammatic  Section  of  the  Human  Retina.    {After 
M,  Schulize  and  Schdfer.) 


226       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

From  the  two  previous  diagrams  it  will  be  seen  that, 
as  in  Szczepanik's  apparatus,  the  rays  of  light  are  broken  up 
and  deflected  at  various  angles  before  they  reach  the 
pigmented  cells  or  the  rods  and  cones,  and  I  assume  that, 
having  arrived  at,  as  it  were,  a  terminal,  they  are,  at  that 
terminal,  transformed  into  waves  of  neuro-electricity, 
which,  picked  up  by  the  rods  and  cones,  are  conveyed  in 
that  form  to  the  brain. 

If  something  of  that  kind  does  not  occur  we  are  con- 
fronted with  another  very  extraordinary  coincidence. 

In  the  Science  of  Light,  by  Percy  Phillips,  D.Sc,  it  is  said : 
"  If  we  suppose  that  the  sensation  of  light  is  due  somehow 
to  the  vibrations  of  electrons  in  the  retina,  the  retina  itself 
will  do  instead  of  a  prism  for  drawing  out  a  pulse  into 
waves,  and  so  we  may  have  interference  even  without  the 
prism.  We  see,  therefore,  that  it  is  just  as  simple  to 
imagine  that  the  regular  trains  of  waves  are  produced  by 
the  receiver  as  by  the  transmitter  of  the  wave.  We  only 
need  assume  regularity  of  period  in  one  or  other  of  them." 

The  theory  that  the  sensation  of  sight  is  due  to  the 
direct  action  of  the  vibrations  of  electrons  in  the  retina 
calls  for  examination.  It  has  not  been  finally  and  con- 
clusively proved  that  light  consists  of  short  electro-magnetic 
waves.  The  strongest  argument  in  its  favour  is  Maxwell's 
calculation  that  the  speed  of  electro-magnetic  waves  agrees 
with  that  of  light,  i.e.,  300,000,000  metres  per  second. 
That  is  equivalent  to  a  velocity  of  12,000,000,000  in.  per 
second,  and  taking  the  distance  between  the  lens  of  the  eye 
and  the  receptive  organ  or  organs  of  the  brain  to  be,  say, 
6  in.,  impulses  would,  according  to  that  theory,  be  trans- 
mitted in  2  000  millionth  of  a  second. 

Moreover,  these  electro-magnetic  waves  would  impinge 
directly  upon  the  layer  of  optic  nerve-fibres,  thence  upon 
the  optic  nerve-cells,  and  exert  their  electronic  vibratory 
influence  upon  five  other  layers  of  the  retina  before  reaching 


ANIMAL  AND   VEGETABLE  227 

the  rods  and  cones,  which  we  are  told  are  the  structures 
directly  concerned  with  vision. 

In  the  conversion  of  rays  of  light  into  waves  of  neuro- 
electricity  delays  which  would  reduce  the  rate  of  trans- 
mission to  the  normal  velocity  of  nervous  impulse  would 
most  certainly  occur  at  the  synapses,  and  quite  apart  from 
physiological  research  we  can  be  reasonably  sure  that  the 
impulses  to  which  vision  is  due  do  not  travel  at  anything 
like  the  rate  at  which  electro-magnetic  waves  are  pro- 
pagated. Halliburton  says  :  "  The  duration  of  the  sensa- 
tion produced  by  a  luminous  impression  on  the  retina  is 
always  greater  than  that  of  the  impression  which  produces 
it.  However  brief  the  luminous  impression,  the  effect  on 
the  retina  always  lasts  for  about  one-eighth  of  a  second." 
That  is,  in  perfect  harmony  with  an  electrical  impulse, 
which,  as  we  have  seen  (p.  160),  always  takes  longer  to 
leave  the  circuit  than  it  did  to  enter  it,  but  it  is  not  in 
harmony  with  the  theory  that  impulses  are  conveyed  to  the 
brain  at  a  velocity  of  300,000,000  metres  instead  of  120 
metres  per  second.  In  the  one-eighth  of  a  second  during 
which  the  retina  retains  the  impression  no  fewer  than 
1,500,000,000  impulses  would  be  produced  by  the  direct 
vibrations  of  electrons,  and  they  would  continue  to  arrive 
at  the  same  speed  while  vision  lasted. 

Some  further  arguments  in  favour  of  the  theory  I  have 
advanced  may,  however,  be  adduced. 

I  have  said  that,  in  my  opinion,  the  optic,  like  the 
auditory,  nerves — and  we  must  include  their  processes — 
are  "  closed "  circuits.  Halliburton  states  that  the 
retina  "  possesses  a  store  of  potential  energy  which  the 
stimulus  serves  to  fire  off."  That  is  understandable  in  a 
closed,  but  not  in  an  open,  circuit. 

"  Nothing  is  known  about  the  yellow  pigment  of  the 
yellow  spot,"  but  a  "  change  produced  by  the  action  of 
light  upon  the  retina  is  the  movement  of  the  pigment  cells. 


228       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

On  being  stimulated  by  light  the  granules  of  pigment  in  the 
cells  which  overlie  the  outer  part  of  the  rod  and  cone  layer 
of  the  retina  pass  down  into  the  processes  of  the  cells, 
which  hang  down  between  the  rods  "  (see  Fig.  119) ; 
"  these  melanin  ovfuscin  granules  are  generally  rod-shaped, 
and  look  almost  like  crystals.  In  addition  to  this,  a 
movement  of  the  cones  and  possibly  of  the  rods  occurs  ;  in 
the  light  the  cones  shorten,  and  in  the  dark  they  lengthen." 
(Halliburton  :    Engelmann.) 

The  property  of  transforming  rays  of  light  into  nervous 
impulses  may  reside  in  the  "  visual  purple,"  but  if  the 
pigment  cells  have  no  part  in  this  and  are  designed  merely 
to  provide  the  dark  lining  of  the  camera,  why  should  they 
be  given  movement,  and  why  do  they  have  processes 
connecting,  functionally  if  not  structurally,  with  the  rod 
and  cone  layer  ? 

The   Ear. 

The  ear  is  divisible  into  three  parts:  i.e.,  the  external 
ear,  the  middle  ear  or  tympanum,  and  the  internal  ear  or 
labyrinth.  Physiologically  described,  "  the  filaments  of 
the  auditory  nerve  end  in  peculiar  structures  buried 
deeply  in  the  hard  portion  of  the  temporal  bone  of  the 
skull,  and  special  arrangements  exist  for  conducting  waves 
of  sound  to  this  deeply  seated  sensitive  part-  The  external 
ear  assists  in  collecting  sonorous  vibrations  that  pass  along 
a  channel  termed  the  external  auditory  meatus,  and 
impinge  against  a  stretched  membrane  called  the  tympanic 
membrane,  or  drum-skin.  The  vibrations  thus  set  up  in 
the  tympanic  membrane  are  transmitted  across  the 
tympanic  cavity  or  middle  ear  by  a  chain  of  small  bones 
— the  m.alleus  or  hammer,  the  incus  or  anvil,  and  the 
stapes  or  stirrup — to  the  inner  ear.  The  membranous 
base  of  the  stapes  is  placed  in  connection  with  the  inner 


ANIMAL  AND   VEGETABLE 


229 


ear  by  being  fixed  into  an  oval  opening  in  a  bony  tubular 
labyrinth  consisting  of  parts  termed  the  vestibule,  the 
semicircular  canals,  and  the  cochlea.  Inside  the  bony 
labyrinth  is  a  nearly  similar  labyrinth  of  membrane  filled 
with  liquid,  a  liquid  also  lying  between  the  bony  and  the 
membranous  labyrinth." 


Fig.  123. — ScHEiiE  OF  THE  Organ  OF  HEARING.    (Landois  and  Stirling.) 

HG,  external  auditory  meatus  ;  T,  tympanic  membrane  ;  malleus 
with  its  head,  short  process  (kf),  and  handle  (m)  ;  a,  incus  with  its 
short  process  (x)  and  long  process — the  latter  is  united  to  the  stapes  (s) 
by  means  of  the  Sylvian  ossicle  (2)  ;  P,  middle  ear  ;  o,  fenestra  ovalis  ; 
r,  fenestra  rotunda  ;  .r,  beginning  of  the  lamina  spiralis  of  the  cochlea  ; 
pi,  its  scala  tympani,  and  vt,  its  scala  vestibuli ;  V,  vestibule  ;  S,  saccule  ; 
U,  utricle  ;  H,  semicircular  canals  ;  TE,  Eustacliian  tube.  The  long 
arrow  indicates  the  line  of  traction  of  the  tensor  tympani  ;  the  short 
curved  one,  that  of  the  stapedius. 

These  liquids  are  known  as  endolymph  and  perilymph 
respectively,  and  according  to  Landois  and  Stirling  the 
end-organs  of  the  acoustic  nerve  lie  in  the  endolymph  and 
on  membranous  expansions  of  the  cochlea  and  semi- 
circular canals. 

"  The  vibrations  conveyed  to  this  fluid  by  the  move- 
ment of  the  base  of  the  stapes  excite  the  peculiar  epithelium 
of  the  inner  sm'face  of  the  membranous  labyrinth,  on  and 
in  which  are  distributed  the  auditory  nerve-filaments. 
Impulses  pass  from  these  filaments  along  the  nerve  lying 
in  the  internal  meatus  to  the  brain,  and  there  produce  that 


230      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

modification  of  consciousness  which  we  call  the  sensation 
of  sound."     (Thornton.) 

Landois  and  Stirling  say  :  "  Normal  hearing  takes 
place  through  the  external  auditory  meatus.  The  enor- 
mous vibrations  of  air  first  set  the  tympanic  membrane  in 
vibration  ;  this  moves  the  malleus  (Fig.  123),  whose 
long  process  is  inserted  into  it ;  the  malleus  moves  the 
incus  (a),  and  this  the  stapes  (s),  which  transfers  the  move- 
ments of  its  plate  to  the  perilymph  of  the  labyrinth." 

All  this,  up  to  and  including  the  movements  of  the 
stapes,  is  perfectly  consistent  and  indeed  almost  identical 
with  a  telephone  receiver  and  microphone  attachment, 
but  when  it  becomes  a  question  of  transfer  of  mechanical 
vibrations  to  nerve-filaments,  or  to  the  wires  of  a  closed 
circuit,  I  would  point  out  that  there  is  no  evidence  that  the 
true  function  of  a  nerve  is  to  convey  mechanical  impulses. 
The  physiological  theory  is  that  the  nerve  impulse  is 
chemical.  My  contention  is  that  it  is  neuro-electrical.  It 
is  difficult  to  understand  how  mechanical  vibrations  can 
be  transformed  into  chemical  impulses,  but  not  at  all 
difficult  to  conceive  them  being  neuro- electrically  trans- 
mitted over  a  closed  telephone  circuit. 

Thornton  remarks :  "  The  whole  subject  of  the 
mechanism  of  hearing  is  far  from  being  satisfactorily 
settled.  .  .  .  For  hearing  the  stimulus  is  of  a  mechanical 
nature."  I  venture  to  think  that  the  utmost  that  can  be 
said  in  favour  of  this  hypothesis  is  that  mechanical 
stimulus  extends  from  the  external  meatus,  by  the  endo- 
lymph,  to  the  auditory  nerve.  It  is  the  nerve,  not  the 
endolymph,  which  conveys  the  stimuli  to  the  brain. 

I  can  offer  one  very  convincing  proof  that  in  this  case 
at  least  the  impulse  is  neuro-electrical.  In  purely  nerve 
deafness  the  measure  of  nervous  energy,  as  shown  by  the 
hand-to-hand  galvanometric  deflection,  is  not  more  than 
30  or  40  mm.  ;    deflections  from  the  back  of  the  cartilage 


ANIMAL  AND   VEGETABLE  231 

of  the  external  meatus,  where  it  adjoins  the  mastoid,  being 
in  accordance  with  that  deflection,  or,  in  other  words,  no* 
exhibiting  departure  from  Ohm's  law. 

In  such  cases,  if  a  rod  of  specially  prepared  carbon  is  held 
by  the  patient  for  a  few  moments  in  the  right  hand  so  that 
the  body  may  receive  a  charge  of  the  form  of  energy 
exerted  by  it,  the  hand-to-hand  deflection  will  rise  to  over 
300  mm.  positive,  and  hearing  will  usually  return  at  once 
and  remain  normal  during  such  time  as  the  charge  is 
retained. 

Halliburton  says  :  "  The  external  and  middle  ears  are 
conducting  ;  the  internal  ear  is  conducting  and  receptive. 
In  the  external  ear  the  vibrations  travel  through  air  ;  in 
the  middle  ear  through  solid  structures — membranes  and 
bones  ;  and  in  the  internal  ear  through  fluid,  first  through 
the  perilymph  on  the  far  side  of  the  fenestra  ovalis,  and 
then  the  vibrations  pass  through  the  basilar  membrane 
and  membrane  of  Reissner,  and  set  the  endolymph  of  the 
canal  of  the  cochlea  in  motion." 

With  great  reluctance  I  must  to  some  extent  disagree. 
The  external  ear,  in  my  view,  is  receptive,  in  the  sense  that 
the  transmitter  of  a  telephone  is  receptive  of  sound  ;  the 
middle  ear  is  receptive  and  conducting — as  a  microphone 
receives  and  conducts  ;  while  the  inner  ear  transforms  the 
vibrations  transmitted,  and  probably  amplified,  by  the 
middle  ear  or  microphone,  into  neuro- electrical  impulses^ 
and  conveys  them  in  that  form  to  the  brain. 

One  thing,  I  think,  can  be  regarded  as  certain.  The 
sensory  nerves,  and  the  nerves  of  special  sense,  are 
"  closed  "  circuits.  That  being  so  it  follows,  logically, 
that  the  quantity  of  endolymph  or  perilymph,  or  both,  in 
the  cochlea  must  not  undergo  diminution — that  is  a  matter 
of  the  chemistry  of  the  body — and  that  the  neuro-electrical 
pressure,  or  electromotive  force,  present  in  those  "  closed  " 
circuits  and  energising  the  endolymph  and  (or)  perilymph 


232      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

must  be  fully  maintained,  if  normal  conditions  are  to  be 
preserved. 

Supposing  any  "  faults  "   to   occur,   at  least  three  of 
them  should  be  susceptible  to  electro -diagnosis — 

(1)  The  drum  of  the  ear  may  be  thickened  or  overlaid 

by  inflamed  tissue  due  to,  say,  inflammation  or 
rheumatoid  conditions. 

(2)  The  bones  of  the  middle  ear  may  be  clogged  by 

catarrh,  or  urates,  so  that  they  are  not  free  to 
vibrate ;    or 

(3)  The  auditory  nerve,  or  line  wire,  may  be  faulty. 

In  either  case  the  vibrations  do  not  reach  the  brain 
unimpaired,  because — 

(1)  They  are  partly  or    wholly  stopped,    or  rendered 

"  woolly  "  by  the  drum. 

(2)  If  responded  to  by  the  drum  they  fail  to  set  fully 

in  motion  the  clogged  bones  of  the  middle  ear, 
or  at  all  ;    or 

(2)  The  faulty  line  wire  fails  to  carry  them  fully,  or 
at  all,  to  the  brain. 

We  have,  then,  at  least  three  morbid  conditions  to  deal 
with,  and  when  one  of  these  conditions  occurs  the  telephone 
system  must  be  tested  and  the  nature  and  locality  of  the 
"  fault  "  ascertained. 

If  the  drum  of  the  ear  is  thickened,  or  the  passage  to  it 
swollen,  by  rheumatoid  arthritis  or  other  causes  con- 
tributory to  local  pyrexia,  it  will  yield  an  abnormal,  that 
is  to  say  a  high,  deflection.  So  will  the  middle  ear — tested 
by  placing  a  suitable  electrode  between  the  mastoid  and 
the  cartilage  of  the  external  ear — if  it  is  affected  by 
catarrh ;  or  it  will  give  a  subnormal  deflection  when  the 
bones  are,  and  have  been  for  some  time,  clogged  by  urates. 
In  much  the  same  way  the  inner  ear  (the  line  wire)  can  be 
made  to  disclose  its  degree  of  conductivity  by  giving  the 


ANIMAL   AND   VEGETABLE  233 

measure  of  the  nerve-current  in  it  as  compared  with  the 
nerve-current  present  in  the  auditory  nerve  of  a  healthy- 
person  of  similar  hand-to-hand  deflection.  If  it  is  partially 
atrophied  the  first  step  should,  I  think,  be  to  restore  it  to 
its  normal  condition  of  an  active  closed  circuit  ;  by,  say, 
ionic  medication. 

In  the  case  of  catarrh  of  the  middle  ear,  or  of  the 
presence  of  inspissated  mucus  in  the  middle  ear,  our  object 
should  be  to  introduce  a  harmless  solvent  into  what  is, 
practically,  a  closed  cavit^^ 


234       STUDIES  IN   ELECTRO-PHYSIOLOGY: 


Chapter  XVII 
ELECTRO  DIAGNOSIS 

THE   GALVANOMETER   AND    ELECTRODES 

AND  How  TO  Use  Them 

The  chief  requirements  in  a  galvanometer  are  great 
sensibility  and  perfect  insulation  combined  with  a  short 
period  of  oscillation.  There  are  several  types,  but  in 
practice  I  prefer  for  research  work  the  special  form  of 
Kelvin  reflecting  Astatic,  made  for  me  by  Elliott  Bros., 
although  it  is  somewhat  expensive.  This  instrument  is 
designed  for  tests  where  specially  good  insulation  of  all 
parts  of  the  circuit  is  required.  There  are  eight  coils, 
having  a  total  resistance  of  from  60,000  to  100,000  ohms, 
carried  in  hinged  frames  supported  by  ebonite  pillars  ; 
four  terminals  carried  on  tall  ebonite  stems  through  the 
top  of  the  case,  and  a  long  suspension. 

The  medical  practitioner  will  be  quite  safe,  as  regards 
sensibility,  in  ordering  an  instrument  which  will  give  a 
deflection  of  4,000  or  more  mm.,  at  a  scale  distance  of 
1  metre,  per  micro-ampere.  The  period  should  not  be 
more  than  seven  seconds. 

On  the  next  page  will  be  found  an  illustration  of  the 
instrument  I  have  mentioned. 

As  shown  it  is  not  adjusted.  To  do  this  it  is  necessary 
that  it  should  be  placed  in  the  east  (facing  west),  looking 
towards  the  scale  which  is  from  1  metre  to  41  in.  distant. 
If  it  is  stood  upon  wood  the  levelling  screws  should  rest  in 


ANIMAL   AND   VEGETABLE 


285 


ebonite  cups,  but  a  good  plan  is  to  let  a  slate  or  marble 
slab  into  the  wall  and  stand  the  galvanometer  upon  it. 

At  the  base  of  the  instrument  are  two  spirit-levels,  and 
the  next  thing  to  be  done  is,  by  manipulation  of  the 
levelling  screws,  to  see  that  each  air-bubble  lies  exactly  in 
the  centre. 


Fig.  124. 


Rising   from   the  top   of  the   case  will   be   seen  four 
terminals    and    a     central    brass    pillar.      Unscrew    the 


236      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

latter.  Beneath  it  is  a  pin,  with  a  milled  head  (Fig.  125)  to 
which  the  suspension  is  attached.  Raise  this 
pin,  without  turning,  very  gently,  until  the  mirror 
"p  is  exactly  in  the  centre  of  the  opening  and 

the  suspension  swings  freely.     Then  replace, 
and  adjust  the  controlling  magnet — shown 

Fis.  125. 

underneath  the  instrument  m  the  figure  given. 

To  do  this  take  off  the  screw  at  the  top  of  the  rod  and 
slide  the  magnet  off.  Then  screw  the  rod  into  its  seat, 
replace  the  magnet — due  north  and  south — and  the  screw 
and  the  galvanometer  is  nearly  ready  for  use. 

Should  it  be  necessary  at  any  time  to  examine  the 
suspension,  first  take  off  the  two  screws  which  clamp  the 
case  to  the  base,  remove  the  terminals  and  the  ebonite 
discs  below  them  and  the  pillar,  having  first  detached 
the  controlling  device  b}^  sliding  off  the  magnet  and 
unscrewing  the  rod.  The  case  can  now  be  lifted  off 
bodily. 

The  next  procedure  is  to  remove  the  coil  connection  at 
the  left-hand  inner  terminal,  and,  also  on  the  left,  there 
is  a  screw  with  a  milled  head.  V/hen  this  is  taken  out  the 
front  coils  will  swing  to  the  right  on  their  hinges  and  expose 
the  suspension. 

Sometimes  a  hair,  a  microscopical  fragment  of  silk  from 
the  suspension,  may  connect  some  part  of  the  latter  with 
the  casing  and  give  trouble.  Upon  opening  the  coils  this 
may  be  detected. 

A  hole,  covered  by  a  slide,  at  the  top  of  the  case  is  for 
the  insertion  of  a  thermometer. 

As  the  Kelvin  galvanometer  is  so  well  known,  a  tech- 
nical description  of  it  is  unnecessary.  There  are  several 
points  in  connection  with  it,  however,  to  which  attention 
may  usefully  be  called. 

If  the  instrument  is  placed  in  the  east  and  facing  west 
the  suspension  will,  before  the  controlling  magnet  is  in 


ANIMAL  AND   VEGETABLE  237 

position,  come  to  rest  in  the  plane  of  the  magnetic  meridian, 
because  very  small  permanent  magnets  are  affixed  trans- 
versely thereto,  and  must,  consequently,  fall  into  line  with 
the  earth's  magnetism.  The  purpose  of  the  controlling 
magnet  is  to  obtain  a  position  in  which  it  quite  neutralises 
the  earth's  magnetism.  To  adjust  zero,  therefore,  a  rough 
approximation  to  it  should  be  made,  before  the  controlling 
magnet  is  in  place,  by  turning  the  milled  suspension  pin 
to  the  right  or  left  as  the  case  may  be — but  avoiding  any- 
thing approaching  a  complete  tm'n — then  putting  on  the 
controlling  magnet  and  moving  it  gently  out  of  the  north 
and  south  until  the  reflected  spot  of  light  nears  the  zero  of 
the  scale.  Further  and  more  delicate  adjustments  may  be 
made  by  turning  the  screw  at  the  back  of  the  pillar,  and 
that  operating  the  ratchet  upon  the  scale-stand. 

Sensibility  may  be  varied  by,  also  very  gently,  moving 
the  controlling  magnet  up  or  down  its  support. 

Advantage  may  be  taken  of  the  equal  number  of  coils 
to  make  the  instrument  differential.  That  is  to  say,  by 
using  the  two  sets  of  coils  separately  one  current  may  be 
sent  in  one  direction  and  another  cmTent  in  the  opposite 
direction,  so  that  comparison  may  be  made  of  their  respec- 
tive strengths.  If  both  are  exactly  equal  there  will  be  no 
deflection,  but  if  one  is  stronger  than  the  other  the  spot  of 
light  will  travel  over  the  scale  and  indicate  the  excess. 
By  preliminary  experiment  the  direction  of  deflection  by 
each  current  can  be  determined  separately,  and  in  this  way 
the  difference  of  intensity  between  the  two  ascertained. 

In  experienced  hands  this  galvanometer  is  as  near 
perfection  as  anything  made  by  man  can  be,  but,  unlike 
those  of  the  moving-coil  type,  it  is  directly  affected  by  any 
outside  vehicle  of  magnetic  or  electrical  energy.  The 
near  proximity  of  a  steel  key  or  even  a  steel  trousers' 
button  is  sufficient  to  cause  a  movement  of  the  light,  and 
so   sensitive   is   it  to  induction  that   it  cannot  be    used 


238      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

satisfactorily  within  three-quarters  of  a  mile  of  an  electric 
railway  or  tube  or  charging  station  by  reason  of  the 
frequent  alteration  of  load.  It  is  true  that,  as  the  human 
body  is  similarly  affected,  the  argument  must  also  apply  to 
any  galvanometer,  but  in  research  work  one  is  not  always 
testing  the  human  body,  or  dealing  with  such  infinitesimal 
electromotive  forces  and  currents. 

The  cost  price  of  this  form  of  Kelvin  is  about  £30. 

We  will  now  consider  an  instrument  of  the  d'Arsonval 
type,  which,  with  equal  sensibility,  can  be  bought  for 
about  £10. 


Fig.  126. 
In  this  the  reflecting  mirror  does  not  carry  a  magnet, 
but  is  directly  connected  with  the  coil,  which,  as  will  be 
seen,  is  suspended  between  the  poles  of  two  laminated  bar- 
magnets.  At  the  suspension-head  there  is  a  milled  pin,  by 
means  of  which  the  suspension  may  be  raised  or  lowered, 
and  a  movable  head  which  may  be  turned  one  way  or  the 
other  to  adjust  the  zero.  No  spirit-levels  are  provided,  but 
the  instrument  may  be  levelled  by  placing  a  small  spirit- 
level  upon  the  base — as  shown  in  the  other  instrument — 
and  testing  it  by  means  of  the  levelling  screws,  taking  care 
that  the  coil  swings  freely  and  is  equi- distant  between  the 


ANIMAL   AND   VEGETABLE 


289 


poles  of  the  magnets.     The  cover  is  then  replaced  and 
clamped  on  with  the  screws  provided  for  the  purpose. 

The  Scale. 
It  is  clear  that  a  light  must  be  thrown  upon  the  mirror  of 
the  galvanometer  and  reflected  back  upon  the  scale.     There 
are  two  ways  of  doing  this.     One  is  to  have  the  direct 
light  at  the  back  of  the  scale,  thus — 


Fig.  127. 

This  is  a  cheap  pattern  of  scale,  but  is  quite  useful  for  all 
purposes  where  the  observer  can  place  himself  close  to  it. 
In  testing  the  human  body,  however,  the  positions  of  the 
galvanometer,  the  scale,  and  the  patient  in  relation  to  the 
observer  have  to  be  considered,  and  it  will  be  evident  that 
with  the  patient  several  feet  away  from  the  scale  the 
observer  must  be  at  some  disadvantage.  To  obviate  this 
difficulty  it  is  better  to  have  a  transparent  scale  (Fig.  128). 

It  has  a  mirror  upon  a  universal  joint.  The  lamp  faces 
the  same  way  as  the  galvanometer.  Its  light  is  thrown 
upon  the  scale,  reflected  therefrom  upon  the  mirror  of  the 
galvanometer,  and  thence  back  to  the  scale.  The  height 
of  the  scale  is  adjustable,  and  there  is  a  ratchet  arrange- 
ment to  move  the  scale  itself  some  inches  to  get  a  true  zero. 


240       STUDIES  IN   ELECTRO-PHYSIOLOGY 


■a.  i^f 


Fig.  129. 


ANIMAL  AND  VEGETABLE 


241 


In  this  way,  almost  irrespective  of  the  position  of  the 
patient,  the  operator  can  be  within  easy  reading  distance  of 
the  scale. 

The  Lamp. 

The  temptation  to  have  an  electric  lamp,  preferably 
affixed  to  the  scale-stand,  is  great.  It  offers  the  advantages 
of  a  brighter  spot  and  less  halation,  but  there  is  always 
the  danger  of  leakage,  and  for  this  reason  I  recommend 
a  paraffin  lamp.  A  useful  type  is  Fig.  129.  There  is 
a  lens,  across  which  there  is  a  vertical  wire  so 
that  the  spot  of  light  upon  the  scale  appears 
as  in  Fig.  1 30  ;  but  it  is  better,  in  avoidance  of 
halation,  to  paint  the  lens  with  dead-black, 
leaving  only  a  vertical  line  ^  in.  wide  in  the 
centre.  The  spot  then  appears  as  in  Fig.  131,  and  can  be 
more  conveniently  and  accurately  read. 

The  Short-Circuit  Key. 

Fig.  132  shows  a  very  useful  and  reliable 

form  of  short-circuit  key,  but  I  have  found  a 

Fig.  131.       cheaper   pattern  answer   quite   satisfactorily 

upon  substituting  a  brass  bar  for  the  ebonite  one  shown 

in  the  front  of  Fig.  183. 


Fig.  132.  Fig.  133. 

Shunts. 
For  research  work  a  shunt  in  terms  of  the  galvano- 
meter, and  proportions  of  ^,  ^V>  and  9^9,  is  desirable  for 
use  in  conjunction  with  the  high-resistance  instrument. 

R 


242       STUDIES  IN   ELECTRO-PHYSIOLOGY: 

For  electro-diagnosis,  however,  a  shunt  is  unnecessary, 
and  as  the  resistance  of  the  coil  of  a  d'Arsonval  galvano- 
meter seldom  exceeds  2,000  ohms,  it  should  not  be  used 
with  that  type  of  recording  instrument  at  all.  If,  however, 
it  is  desired  to  do  so,  a  "  universal  "  shunt  is  recommended. 
It  is  a  golden  rule  to  "  limit  the  apparatus."  To  avoid 
leakage  is  to  avoid  trouble.  Let  the  top  of  the  testing- 
table  be  of  teak  or  other  hard  wood,  and  paraffin-wax  it. 
Also  have  a  gas-fire  or  electric  radiator  in  the  testing-room 
and  maintain  a  standard  temperature. 

Connecting  Wires. 

To  connect  the  galvanometer  with  the  short-circuit  key 
and  electrodes  use  the  best  electric  light  flex  (80  to  40), 
untwisting  same  so  as  to  have  single  wires. 

Earth  Connection. 

Thick  (preferably  insulated)  copper  wire  soldered  to 
the  water-main  and  the  other  end  brought  and  connected 
to  a  copper  rod  or  tube  in  the  testing-room,  makes  a  very 
good  "  earth." 

The  Electrodes. 

These  are  seven  in  number,  and  are  made  for  me  by 
Messrs.  Hodges  &  Co.,  of  St.  John  Street,  Clerkenwell. 
For  the  hand-to-hand  deflection  I  use  solid  German  silver 


y  y 


Fig.  134. 


rods  (heavily  silver-plated),  5^  in.  by  |  in.,  provided  with 
a  thumb-piece  and  a  terminal  at  the  upper  end  (Fig.  134), 
the  thumb-pieces  being  shaped  as  Fig.  135  in  plan. 


Fig.  135. 


ANIMAL  AND   VEGETABLE  243 

German  silver  has  a  low  co-efficient 
of  increase  of  resistance  with  temperature, 
and,  when  heavily  plated,  is  a  very  suitable 
alloy. 

When  one  of  these  electrodes  is  held  in  each  hand  by  the 
patient  the  thumbs  are  pushed  up  to  the  closed  ends  of 
the  thumb-pieces,  the  fingers  used  merely  in  support  and 
no  pressure  exercised.     The  connections  are  then — 

Oaluano  meter 


£'^ectrade 


£iectrode 


/Su^ec^ 


Fig.  136. 
Short-circuit  key  omitted. 

The  other  electrodes  consist  of  an  elastic  rubber  band,  to 
encircle  the  head,  carrying  a  circular  plate  of  silver  (or 
German  silver  heavily  plated)  1  in.  in  diameter  and 
provided  with  a  terminal  of  the  same  metal  : — 


Fig.  137. 

For  purposes  of  electro-diagnosis  this  is  connected  by  a  wire 
to  one  terminal  of  the  galvanometer,  and  the  band  fitted 
round  the  head  of  the  patient  in  such  mamier  that  the  flat 


244      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

surface  of  the  circular  plate  makes  contact  with  the  centre 
of  the  forehead  ;  the  circuit  being  completed  by  means  of 
another  electrode — 


Fig.  138. 

These,  preferably,  should  be  three  in  number  ;  the 
boss,  a,  having  diameters  of  |  in.,  re  in.  and  xe  in.  respec- 
tively. 

The  readings  obtained,  as  I  explain  later  on,  will  be  in 
conformity  with  the  hand-to-hand  deflection  and  Ohm's 
law. 

In  the  galvanometric  diagnosis  of  morbid  conditions 
the  sign  of  current  is  of  little  importance.  All  the  deflec- 
tions are  comparative.  The  one  thing  that  matters  is  the 
quantity  of  current  issuing  from  any  part  of  the  body,  and 
this  is  shown  by  the  relative  rapidity  of  the  excursion  of 
the  light  upon  the  scale  ;  the  gradations  being  from  a  very 
rapid  off-scale  deflection  in  the  case  of  acute  local  pyrexia 
to  no  deflection  at  all  in  cancer. 

For  diagnosis  I  recommend  the  use  of  a  large  head-plate, 
for  the  reason  that  it  is  imperatively  necessary  to  cover 
the  central  line  in  order  to  obtain  accurate  comparison 
between  two  symmetrical  parts  of  the  body,  but  in  research 
work,  as,  for  instance,  attempting  to  differentiate  efferent 
from  afferent  nerves,  sign  of  current  is  of  the  utmost 
consequence,  and  the  head-plate  must,  therefore,  be  of 
exactly  the  same  area  and  resistance  as  the  electrode  used 
to  complete  the  circuit. 

Formerly  I  had  all  these  "electrodes  made  of  solid  silver, 
but  it  involved  a  quite  unnecessary  expense. 


ANIMAL  AND   VEGETABLE  245 


Chapter   XVIII 
OHM'S   LAW 

In  its  Application  to  the  Human  Body 

As  I  have  frequently  mentioned  Ohm's  law,  and  have 
said  that  all  body  deflections  must  conform  to  it,  I  will,  fo^ 
the  guidance  of  the  medical  practitioner,  explain  it  so  far 
as  may  be  necessary.  _  I  have  given  it,  briefly,  as  C  =  ^  ' 

that  is,  the  current  at  any  point  is  equal  to  the  electro- 
motive force  divided  by  the  resistances  in  circuit  at  that 
point,  assuming  both  electromotive  force  and  resistances 
to  be  constant.  But  that  is  only  a  part  of  Ohm's  law,  and 
we  must  ponder  it  further  to  see  whether  it  in  any  way 
conflicts,  or  in  every  way  agrees,  with  observed  phenomena. 

As  most  of  my  readers  will  be  aware,  the  unit  of  electro- 
motive force  is  called  a  volt,  that  of  resistance  an  ohm,  and 
that  of  current  an  ampere.  The  quantity  of  electricity 
which  flows  per  second  in  a  current  of  one  ampere  is  known 
as  a  coulomb,  and  the  capacity  of  a  condenser  in  which  a 
charge  of  one  coulomb  causes  a  potential  of  one  volt  is 
said  to  be  a  Farad. 

To  put  it  in  terms  of  hydrostatics,  with  which  everyone 
will  be  familiar,  E  is  the  head  of  water  (pressure) ;  R  is 
the  resistance  offered  to  flow  by  the  inner  perimeter  of  the 
pipe  (in  the  inverse  ratio  to  the  sectional  area  of  the  pipe) ; 
C  represents  the  quantity  of  water  flowing  through  the 
pipe  at  any  point,  and  is,  obviously  ^  ;  while  the  coulomb 
may  be  said  to  be  the  unit  of  effective  discharge. 


246      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

Furthermore,  the  Farad  is  a  unit— as,  for  instance,  a 
gallon — of  the  capacity  of  a  cistern  into  which  the  water 
may  be  caused  to  flow  from  E,  and  in  which  the  quantity 
of  one  coulomb  produces  a  pressure  of  one  volt,  by  creating, 
as  it  were,  another  head  of  water  at  a  lower  level. 

For  a  circuit  to  be  established  it  is  necessary  in  the  case 
of  electricity  for  there  to  be  a  return,  either  by  another  wire 
or  by  the  earth  ;  there  must  be  a  "  loop."  Similarly  no 
water  will  flow  from  the  cistern  unless  it  has  access  to  air, 
nor  will  any  water  issue  from  a  pipe  unless  and  until  the 
tap  is  opened  to  air. 

The  resistance  of  a  metallic  conductor  is  directly  pro- 
portionate to  its  length,  is  in  the  inverse  ratio  to  its 
sectional  area,  and  is  expressed  by  R.  There  are,  however, 
resistances  (r)  other  than  that  of  the  conductor  or  conduc- 
tors to  be  taken  into  account,  and  the  principal  of  these 
(outside  the  galvanometer  and  electrodes)  is  the  internal 
resistance  of  the  generating  cell  or  cells.  This  varies  not 
only  with  the  surface  area  of  the  plates  but  in  a  galvanic 
cell  with  the  chemical  composition  of  the  exciting  fluid. 

Briefly  summed  up,  the  E.M.F.  is  proportional  to  the 
current  when  the  resistance  is  constant,  the  E.M.F.  is 
proportional  to  the  resistance  when  the  current  is  constant, 
and  the  E.M.F.  is  proportional  to  the  product  of  current 
strength  and  resistance  when  both  vary. 

The  resistance  of  metals  increases  with  rise  of  tempera- 
ture, while  that  of  liquids  and  dielectrics  decreases  more  or 
less  rapidly. 

When  there  are  two  conductors  of  different  resistance 
joining  two  points,  the  current  in  either  branch  is  inversely 
as  the  resistance  of  that  branch. 

In  reviewing  the  galvanometric  deflections  exhibited  in 
normal  health  by  the  human  body  we  must  bear  in  mind 
certain  facts  of  primary  importance.  The  conductors 
(nerves)  and  condensers  (certain  cells)  are  composed  of 


ANIMAL  AND    VEGETABLE  247 

moist  substances,  and  their  conductivit}-,  instead  of  their 
resistance,  increases  in  a  physiologically  defined  ratio  with 
rise  of  temperatiu'e,  while  the  electromotive  force  fluc- 
tuates during  certain  periods  of  the  twenty -fom-  hours  and 
also  in  accordance  with  the  degree  of  fatigue  to  which  the 
patient  has  been  subjected.  It  will  be  seen,  therefore,  that 
while  R  may  be  constant,  neither  E  nor  C  can  be  said  to  be 
so.  For  this,  if  for  no  other  reason,  the  hand-to-hand 
deflection  must  be  carefully  taken.  When  this  is  done  all 
the  body  deflections  must,  by  Ohm's  law,  be  in  conformity 
with  it. 

Another  point  which  calls  for  consideration  is  the 
capacity  of  our  condenser-ganglion  cells  and  condenser- 
compartment  muscular  fibres.  We  have  seen  that  a 
capacity  of  one  Farad  with  a  quantity  of  one  coulomb 
causes  a  potential  of  one  volt,  and  the  fact  that  we  have  to 
go  into  minute  fractions  of  each  unit  does  not  affect  the  law. 

The  potential  at  any  point  (supposing  R  to  be  constant) 
is  liable  to  variation  by  any  difference  in  E  (producing  a 
difference  in  C),  while  a  rise  or  fall  of  temperature  may  not 
only  alter  the  resistance  of  R,  generally  or  locally,  but  also 
the  internal  resistance  (r)  of  all  or  some  of  the  cells. 

Care,  then,  must  be  taken  when  galvanometric  examina- 
tions are  made  to  observe  the  temperature  of  different  parts 
of  the  body,  as  one  part  may  be  colder  than  another,  and  by 
giving  a  subnormal  deflection  introduce  error  into  diag- 
nosis. Furthermore,  the  utmost  vigilance  must  be  ob- 
served to  ensure  the  conditions  of  contact  being  equal,  as, 
if  one  part  of  the  skin  is  more  moist  than  another,  the 
result,  generally  speaking,  will  be  a  higher  deflection  from 
that  part.  Inversely  the  presence  of  fat  in  the  skin  and 
subcutaneous  tissue  would  tend  to  interpose  resistance  and 
therefore  diminish  the  deflection,  etc. 

We  may  now  proceed  with  our  illustration.  When 
any    amount    of    resistance    is    introduced    between    the 


248       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

terminals  of  a  cell,  the  difference  of  potential  becomes  less 
than  the  total  E.M.F.  observed  when  the  circuit  is  open. 
Assuming  the  current  to  consist  of  a  series  of  polarisations 
and  discharges,  the  chemical  affinities  or  contacts  must  call 
up  the  difference  of  potential  representing  the  whole  E.M.F. 
after  each  discharge.  The  remaining  part  of  the  E.M.F. 
is  really  present  in  the  liquid  of  the  cell,  which  offers 
resistance  to  the  current,  and  in  it  the  potential  follows 
exactly  the  same  laws  as  in  the  solid  part  of  the  circuit. 
To  illustrate  this  we  will  set  off  a  horizontal  line  ABC 


J) 


Jl 


3 


Fig.  189. 


and  a  vertical  line  AD,  representing  the  E.M.F.     AB  is 
the  resistance  of  the  cell  (r),  and  BC  that  of  the  connecting 


Fig.  140. 

arc  (R).     The  line  DC  will  then  give  us  the  potential  at 
every  point  in  the  circuit. 

If  there  are  several  cells  in  compound  circuit,  AB 
represents  the  total  resistance,  and  AD  the  total  E.M.F. 
of  the  battery.  The  line  of  potential  will  not  then  be 
DC,  but  a  broken  line  which  rises  at  each  cell.  Thus, 
supposing  we  have  three  cells,  the  line  of  potential  will 
be  given  by  EF  ;   GH  ;   KC.     (See  above.) 


ANIMAL  AND   VEGETABLE  249 

The  potential  gradient  gives  us  potential  differences, 
and  not  the  absolute  potential  at  any  point.  If  the  cell 
and  circuit  be  all  insulated,  the  potential  at  some  parts 
will  be  +  and  at  the  other  parts  — ,  depending  upon  the 
capacity  of  the  various  parts  of  the  circuit.  If  we  connect 
the  circuit  with  earth  at  any  one  point,  we  have  only  to 
draw  a  line  parallel  to  the  base  line  through  the  correspond- 
ing point  on  the  gradient,  and  perpendiculars  to  this  line 
will  then  give  the  absolute  potential,  positive  when  above 
and  negative  when  below  this  line.  The  figures  drawn 
would  represent  the  potential,  supposing  the  zinc  plate  to 
be  to  earth.     (Cummings.) 

It  is,  of  course,  a  matter  of  extreme  difficulty  to  apply 
Ohm's  law  to  the  human  body  in  the  absence  of  more 
definite  information  as  to  its  electrical  structure  and  in 
view  of  the  changes  which  occur,  even  in  normal  conditions, 
in  its  E.M.F.,  capacity,  and  resistances  ;  but  I  am  con- 
vinced that  when  the  nervous  system  is  studied  on  electrical 
as  v/ell  as  chemical  lines  and  in  relation  to  this  law,  a  great 
advance  will  be  made  in  our  knowledge  of  the  human 
organism . 

Hand-to-Hand  Deflection. 

In  taking  the  hand-to-hand  deflection  several  pre- 
cautions are  necessary — 

(1)  The  patient  should  be  placed  in  contact  with  an 
"  earth  "  of  low  resistance  for  five  or,  preferably,  more, 
minutes  before  testing.  A  copper  rod  or  tube  connected 
by  an  insulated  wire  (with  a  thick  conductor)  to  the  water- 
main  makes  a  very  good  "  earth." 

(2)  Rings  must  be  removed  from  the  fingers,  as  they 
introduce  difference  of  contact ;  and  all  steel,  such  as  keys 
and  knives,  from  the  pockets,  as  steel  is  always  more  or 
less  magnetic.  Gold,  silver,  and  copper  coins  do  not 
matter. 


250       STUDIES  IN  ELECTRO-PHYSIOLOGY: 

(3)  The  hands,  after  "  earthing,"  must  be  washed  with 
soap  and  water,  and  not  only  dried  with  a  towel  but  given 
an  interval  of  at  least  five  minutes  before  testing. 

(4)  During  the  time  that  the  subsequent  testing  of 
the  body  takes  place  it  is  desirable  that  the  number  of 
persons  in  the  testing-room  should  be  limited  to  the 
patient  and  the  observer.  But  this  is  not  always  possible. 
In  certain  cases  a  medical  attendant  and  a  female  friend  or 
a  nurse  must  be  present,  but  in  these  cases  such  persons 
should  be  stationed  as  far  from  the  patient  as  possible,  and 
not  admitted  to  the  testing-room  until  the  hand-to-hand 
deflection,  both  as  regards  sign  and  quantity,  has  been 
accurately  determined. 

Application  of  Ohm's  Law  to  Solutions. 

Where    E    =  E.M.F.,    and    /    is  the    distance    between 
electrodes. 

Generally  speaking,  "  the  velocity  of  the  ions  is  pro- 

portional  to  the  value  of  the  motive  force  -^ ." 

Such  a  law  as  that  "  the  velocity  with  which  a  particle 
moves  under  the  influence  of  a  certain  force  is  proportional 
to  this  force  "  is  valid  for  all  liquid  or  gaseous  particles 
moving  between  other  liquid  or  gaseous  particles  so  long  as 
collisions  constantly  take  place.  This  law  can  be  derived 
from  the  principles  of  the  kinetic  theory  of  gases,  as  is 
proved  in  treatises  on  internal  friction. 

"  We  must  imagine  the  ions  as  particles  of  a  liquid 
which  receive  an  acceleration  under  the  influence  of  some 
external  force,  electrical  or  osmotic,  and  the  velocity  im- 
parted is  proportional  to  the  force  acting.  The  ions,  like 
liquid  particles  in  general,  become  more  mobile  as  the 
temperature  rises."     (Arrhenius.) 


ANIMAL  AND   VEGETABLE  251 


Chapter  XIX 

THE     INTERPRETATION     OF     CERTAIN 
ELECTRO-PHYSIOLOGICAL  PHENOMENA 

There  are  in  the  human  body  many  structures  and 
substances  which,  although  not  in  themselves  of  very  high 
resistance,  may,  in  view  of  the  low  tension  of  the  nerve- 
current,  be  termed  dielectrics.  Among  these  are  the 
sheaths  of  medullated  and  the  lipoid  coatings  of  non- 
medullated  nerves  ;  the  capsules  and  membranous  cover- 
ings of  and  in  cells  ;  the  sarcolemma  and  neurilemma ; 
Krause's  membranes  of  voluntary  muscular  tissue,  neu- 
roglia processes  and  connective  tissue,  etc. 

The  effect  of  heat  upon  any  and  every  known  dielectric 
is  to  lower  its  resistance. 

To  ascertain,  for  instance,  the  relative  resistance  of 
gutta-percha  at  different  temperatures  we  have  the 
formula — 

Log  R    =  log  r  —  /  log  0-9399 

where  R    =  resistance  at  higher  temperature, 

r    =  resistance  at  lower  temperature,  and 
t    =  difference  in  temperature  in  degrees  F. 

Reduced  to  figures,  the  relative  resistances,  calculated 
from  the  curve,  are  :  75°  F.  =  1-000  ;  90°  F.  =  0-407; 
100°  F.  =  0-223  ;    110°  F.  =  0-137. 

In  acute  inflammation  the  local  temperature — that  is, 
the  temperature  in  the  area  affected — may  rise  at  least  ten 
degrees  F.  above  normal ;  and  this  would,  for  gutta- 
percha, give  us  0-4068  (at  90°  F.)  and  0-2233  (at  100°  F.), 


252      STUDIES   IN   ELECTRO-PHYSIOLOGY: 

or  a  fall  of  nearly  fifty  per  cent,  of  resistance,  or  (roughly) 
five  per  cent,  per  degree. 

Inasmuch  as  the  human  nerve-current  escapes  through 
the  dielectrics  of  the  body,  despite  the  fact  that  the  tension 
is  not  more  than  from  4  to  5  millivolts,  it  is  evident  that 
their  resistance  is  infinitely  lower  than  that  of  gutta- 
percha. 

We  have  no  means  of  determining  with  accuracy  the 
resistance  of  any  of  these  dielectric  structures  or  substances 
in  their  natural  and  normal  environment,  nor,  while  we 
know  that  a  rise  of  temperature  affects  them  adversely, 
must  we  at  once  assume  that  the  relative  fall  in  resistance 
of  a  nerve-sheath  is  the  same  as  that  of  gutta-percha. 
Maxwell's  recent  experiments,  however,  went  to  show  that 
a  rise  of  10°  C.  approximately  doubled  the  velocity  of 
nerve-conduction  by  lowering  the  resistance  of  the  nerve- 
substance. 

Heat  decreases  the  resistance  of  liquid  and  increases  the 
resistance  of  metallic  conductors  in  a  known  ratio.  Com- 
paring a  nerve  with  a  copper  wire,  the  increase  in  resistance 
of  copper  per  10°  F.  would  be  one-fifth  or  twenty  per  cent. 
=to  two  per  cent,  per  degree,  but  the  fall  in  resistance  of 
gutta-percha  due  to  the  same  increase  is  nearly  fifty  per 
cent.  By  this  process  of  reasoning  we  find  some  ground 
for  the  belief  that  the  effect  of  temperature  upon  the 
dielectrics  of  the  body  is  approximately  the  same  as  upon 
gutta-percha ;  involving  roughly  a  fall  of  five  per  cent, 
per  degree  Fahrenheit  within  certain  limits,  although  I 
believe  the  loss  to  be  much  greater. 

Now,  it  is  quite  obvious  that  if  the  organs  of  the  body 
connected  with  the  transmission  of  im.pulses,  the  mainte- 
nance of  neuro-electrical  equilibrium,  the  conservation  of 
energy,  and  the  contraction  of  muscular  tissue  are  to 
function  properly,  the  temperature  of  every  part  of  the 
whole  organism  must  not  exceed  the  normal,  which  we  may 


ANIMAL  AND   VEGETABLE 


253 


take  to  be,  subcutaneously,  about  100°  F.  Protoplasm 
dies,  I  am  informed,  at  about  114°  F.,  and  as  we  know 
that  cells  do  die  in  the  area  affected  by  acute  inflammation, 
we  have  a  right  to  postulate  that,  in  that  area,  there  may 
be  a  rise  of  temperature  of  at  least  10°  F.  above  the  normal. 

And  with  what  result  ? 

Suppose  a  submarine  telegraph  cable  to  connect  two 
stations,  A  and  B,  and  the  battery  at  the  sending  station, 
A,  to  have  just  sufficient  E.M.F.  to  overcome  the  resistance 
and  allow  for  the  leakage  of  the  cable  and  actuate  the 
receiving  instrument  at  B.  What  would  happen  if  at  some 
point  intermediate  between  A  and  B  the  dielectric — the 
gutta-percha — of  the  cable  became  heated  to  110°  F.  ? 
There  would  be  a  loss  of  fifty  per  cent,  of  its  insulation,  an 
escape  to  earth  at  the  fault  and  interrupted  or  faulty 
communication  with  B.  The  following  diagrams  will  make 
this  clear,  assuming  the  leak  to  be  equidistant  between 
A  and  B— 


^'''V^. 


f/<r^/, 


^a/ 


formal  Condtfton 
Fig.  141. 


Abnormal  Condition 
Fig.  U2. 

That,  approximately,  is  what  occurs  when  the  resistance 
of,  say,  a  nerve-sheath,  or  the  coating  of  a  non-medullated 
nerve,  is  partly  broken  down  by  the  rise  of  temperature 


254      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

incidental  to  inflammation,  and  as  a  consequence  the 
nervous  impulse  or  current  is  not  conveyed  at  normal 
pressure  to  its  destination,  to  supply  blood-vessels,  to 
actuate  muscular  fibres,  or  to  energise  or  transmit  messages 
to  various  cell-groups. 

Nor  is  this  the  full  extent  of  the  mischief.  The  current 
escaping  through  the  fault,  in  conformity  with  natural 
laws,  seeks  the  path  of  least  resistance  to  earth  (air),  and 
from  that  point  throughout  that  path  the  cells  are  in  a 
highly  electrified  area,  and,  their  insulation  not  being 
capable  of  withstanding  the  strain,  they  in  all  probability 
become  over-ionised.  A  condition  is  thus  created  favour- 
able to  the  multiplication  of  inimical  bacteria  and 
unfavourable  to  phagocytosis. 

The  path  of  least  resistance  must  be  from  the  fault 
through  the  intervening  tissues  and  the  skin,  to  air,  and 
generally,  it  will  be  the  shortest  path.  But  wherever  it  is 
it  is  clear  that  an  abnormal  quantity  of  current  must  issue 
from  that  part  of  the  skin  in  which  the  "  path  "  terminates, 
and  that  if  we  place  the  circular  plate  upon  the  centre  of 
the  forehead  of  the  patient  in  order  to  be  sure  of  getting 
on  the  central  line,  and  another  electrode  upon  the  affected 
area — both  electrodes  being,  of  course,  connected  to  the 
galvanometer — the  fault  will  manifest  itself  by  a  more  or 
less  rapid  excursion  of  the  light  upon  the  scale  ;  that  is  to 
say,  the  rapidity  of  the  excursion  will  be  proportionate  to 
the  quantity  of  neuro-electricity  escaping,  and  that  quan- 
tity will  also  be  proportionate  to  the  rise  of  local  tempera- 
ture or  to  the  degree  in  which  local  insulation  resistance 
has  been  broken  down  by  temperature. 

Let  us,  for  example,  take  a  case  of  lobar  pneumonia, 
the  base  of  the  right  lung  being  affected  (Fig.  143). 

Here,  after  taking  the  hand-to-hand  deflection,  we  are 
able  to  make  intelligent  comparison  of  the  galvanometric 
readings  from  the  affected  and  the  unaffected  lung,  or  at 


ANIMAL  AND   VEGETABLE  255 

all  events  from  two  symmetrical  parts  of  the  chest  and  back. 
Whatever  the  hand  reaction  was  the  body  deflections 
would  all  be  lower,  because  of  the  resistance  interposed  not 


fo  Calva  ncmeter 


250"%,  rapid  /  \     80'"/m  s/<w 

^i^/ttbaoe        I       \i  I  \      left  dose 


jTrtalleleclreiie 

/£'OQSS 

t^Gahancmeier. 

Fig.  143. 

only  by  nerve-substance  but  by  sebaceous  glands  and  fat 
cells,  and  in  no  case  would  the  light,  under  normal  con- 
ditions, exhibit  a  ra'pid  movement  upon  the  scale.  In  the 
above  illustration  we  have  obtained  deflections  of  80  mm. 
slow  upon  the  unaffected,  and  250  mm.  ra'pid  upon  the 
affected  side,  and  have  found  the  rate  of  travel  increase  as 
the  electrode  touched  the  skin  on  the  centre  of  the  spot  of 
"least  resistance."  That  would,  with  a  galvanometer  of 
the  sensibility  I  have  described,  postulate  semi-acute 
inflammation  and  indicate  a  fairly  high  local  temperature, 
but  in  a  very  acute  case  the  light  would  be  seen  to  fly  off 
the  scale. 

In  double  pneumonia  there  would  be  a  short-circuit 
between  the  two  lungs,  or  the  affected  parts  of  them,  and 
the  path  of  least  resistance,  common  to  both  lungs,  might 
be  from  the  left  lung  or  the  right,  to  the  skin. 

These  remarks  apply  to  galvanometric  observation  of 
all  forms  of  local  pyrexia.  As  regards  the  exact  internal 
position  of  the  fault,  the  deflections  should,  theoretically, 


256      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

be  the  same  from  the  back  and  front  when  the  **  fault  "  is 
equidistant,  higher  from  the  front  when  it  is  nearer  to  the 
front,  and  higher  at  the  back  when  it  is  nearer  to  the  back» 
but  in  practice  the  conditions  of  contact  must  be  studied 
and  allowance  made  for  them.  As  a  rule,  the  skin  of  the 
back  is  more  oily  or  greasy  than  that  of  the  chest.  A  little 
experience,  however,  will  enable  the  physician  to  make 
correct  diagnosis. 

In  order  to  make  clear  much  of  that  which  in  physiology 
remains  obscure  it  is  only  necessary  to  reason  in  terms  of 
highest  potential  of  nerve-force  in  the  brain  and 
differences  of  potential  in  the  body,  or,  to  put  it  another 
way,  in  terms  of  hydrostatics  ;  the  brain  being  the  con- 
stantly maintained  head  of  water,  the  nerves — the  motor 
and  secretory  paths — the  pipes  through  which  it  flows,  and 
differences  of  potential  being  differences  of  level. 

The  sensory  nerves  may  be  compared  with  pipes  filled 
with  water  at  an  adjusted  pressure,  and  the  impulses 
conveyed  by  them  to  the  brain  to  the  undulations  or 
vibrations  transmitted  through  them  by  reason  of  any 
disturbance  of  that  adjustment. 

Thinking  along  those  lines,  we  may  more  intelligently 
conceive  how  and  why  it  is  that  local  pyrexia  manifests 
itself,  electro-pathologically,  as  an  expression  of  greater 
quantity  of  nerve-current  in  the  part  affected.  It  is  an 
expression  of  lower  level,  because  the  resistance  of  the  path 
is  lowered.  Normally  the  resistance,  if  we  consider  it  as 
level,  would  be  represented  by  the  line  ab  in  the  following 
diagram : — 


.air 

Fig.  143a. 

The  head  of  water — the  vertical  line  au — remains  unaltered 


ANIMAL  AND   VEGETABLE 


357 


throughout,  but  owing  to  local  pyrexia  at  h  the  level  is 
altered  and  the  diagonal  may  become — 


..air 


Fig.  143b. 


giving   the   effect   of  increased  pressure   and   consequent 
greater  flow. 

Not  only  is  this  so,  but  as  a  local  rise  of  temperature 
lowers  the  level  of  issue,  it,  at  the  same  time,  enlarges  the 
diameter  of  the  pipe,  in  the  area  affected,  by  increasing  the 
conductivity  of  the  moist  conductor,  the  nerve-substance  ; 
so  that  we  have  not  only  a  lower  level,  but  what  may  be 
likened  to  an  artificial  head  of  water  created  in  the  path  a,  h. 

Similarly  alterations  of  resistance  in  the  form  of  added 
resistance  due  to  disease  may  be  thought  out.  Between 
acute  local  pyrexia,  such  as  lobar  pneumonia  with  a  body 
temperature  of  106°  F. — involving,  possibly,  a  local 
temperature  of  116°  F. — and  cancer,  there  would  be  the 
widest  margin,  because  the  cancer  cells  are  devoid  of 
conductivity.  In  the  latter  case  our  diagram  might 
become — 


air 


Fig.  143c. 

and  there  would  not  be  any  flow  at  all  from  a  to  h. 

There  are  many  gradations  between  the  two  extremes, 
but  after  due  allowance  has  been  made  for  skin  conditions, 

s 


258       STUDIES   IN   ELECTRO-PHYSIOLOGY: 

sebaceous  glands,  and  so  forth,  it  will  be  found  that 
differences  of  resistance  imply  differences  of  level,  and  that 
those  differences,  as  shown  by  the  galvanometer,  may, 
with  care,  guide  the  way  to  correct  diagnosis. 

Some  physiologists  have  endeavoured  to  explain  wide 
deflectional  differences  as  being  due  to  varying  conditions 
of  contact,  that  is  to  say,  to  the  presence  of  more  or  less 
moisture  in  the  skin.  But  in  pyrexia,  local  or  otherwise, 
moisture  is  conspicuous  rather  by  its  absence  than  its 
presence,  and  it  will  be  found  that  a  hot,  dry  skin  will, 
when  it  is  associated  v/ith  inflammation,  always  give  a 
higher  deflection  than  is  obtainable  from  any  part  of  the 
body  not  so  affected. 

In  febrile  diseases  it  is  generally  the  first  care  of  the 
physician  to  get  the  skin  to  act. 

Moreover,  experience  has  shown  that  in  a  number  of 
cases  of  nervous  asthenia  the  hand-to-hand  deflections, 
despite  the  fact  that  the  palms  were  wet,  were  all  low 
(40  or  50  mm.)  and  all  negative,  reverting  only  to  the 
positive  side  of  the  scale  upon  convalescence. 

Impaired  Conductivity. 

A  converse  condition  is  v/hen  there  is  a  partial  failure 
of  inter-ceilular  conduction,  due  either  to  increased  resist- 
ance of  the  nerve-substance  or  to  some  change  in  the  ionic 
cell  contents  by  which  they  are  rendered  less  active.  It 
very  frequently  happens  that  a  painful  disorder  is  diagnosed 
as  neuritis  or  sciatica  and  that  treatment  gives  no  relief. 
True  neuritis,  as  I  understand  it,  is  an  inflammatory 
condition,  caused  by  the  insulation  resistance  of  a  sheath 
of  nerve  or  nerves  being  interfered  with  by  local  pyrexia. 
In  my  experience  the  neuritis  we  hear  so  much  about  is 
sometimes  not  so.  It  is,  perhaps,  in  five  cases  out  of  ten, 
due  to  some  toxin.  Pyorrhoea,  the  internal  administration 
of  nux  vomica,  post-diphtheritic  poisoning,  inoculation  by 


ANIMAL  AND   VEGETABLE  25© 

certain  sera,  and  chill  are  direct  causes,  and  in  every  case 
the  affected  part  will  yield  a  subnormal  deflection, 
indicating  treatment  by  ionic  medication. 

Various  Faults. 

When  there  is  any  functional  throat  trouble,  asthma, 
or  irregular  action  of  the  heart,  the  vagus  nerves  should 
always  be  tested  by  placing  a  small  electrode  (^  in.  boss) 
directly  below  and  a  little  forward  of  the  angles  of  the  jaw  ; 
while  "  nervous  breakdowns,"  excessive  nervousness, 
insomnia,  and  some  uncertainty  of  movement  may  have 
their  origin  in  spinal  faults  which  can  be  readily  detected. 

I  remember  one  case  of  supposed  epilepsy  (grand-mal) 
in  the  patient  of  a  medical  friend.  The  pulse  was  4-0, 
the  eyes  lack-lustre,  and  fits  (so-called)  were  of  frequent 
occurrence.  Gaivanometric  examination  revealed  a  line 
of  chronic  inflammation  extending  from  the  base  of  the 
cerebellum  to  the  right  cervical .  Under  diel  ectric  treatment 
the  pulse  went  from  40  to  70  in  a  fortnight,  his 
health  became  normal,  and  he  has  since  been  able  to  pursue 
his  avocations.  His  trouble  was  that  when  the  inflamma- 
tion became  acute — as  it  did  from  time  to  time — and  the 
quantity  of  nerve-current  escaping  became  excessive,  he 
fainted. 

I  mention  this  merely  to  emphasise  the  importance  of 
the  galvanometer  in  obscure  morbid  pathology. 

Reverting  for  a  moment  to  the  vagi,  it  must  be  borne 
in  mind  that  they  have  both  efferent  and  afferent  branches, 
and  that  when  they  or  one  of  them  exhibit  a  high  and 
intermittent — both  positive  and  negative — deflection,  it 
inferentially  argues  intermittent  contact  between  those 
branches.  The  afferent  branch  is  sensory  but  the  efferent 
is  not ;  the  escape,  therefore,  from  the  sensory  branch 
might  be  constant  and  that  from  the  efferent  only  active 
when  the  nerve  conveyed  an  impulse. 


260      STUDIES  IN   ELECTRO-PHYSIOLOGY: 

On  Disease  in  General. 

In  connection  with  electro-diagnosis  I  have  postulated, 
both  verbally  and  in  print,  that  any  physical  change  in  the 
body  must  be  attended  by  a  neuro- electrical  change,  which 
can  only  be  galvanometrically  detected  ;  and  that  the 
process  of  restoring  the  one  to  normality  tends,  automatic- 
ally, in  the  great  majority  of  disorders,  to  restore  the 
other  to  normality. 

Disease  is  a  deviation  from  the  state  of  health,  implying 
some  alteration  in  the  functions,  properties,  or  structure  of 
some  organ  or  tissue,  and  may  be  generally  described  as 
an  abnormal  performance  of  the  processes  constituting 
life.  That  being  so,  it  would  be  illogical  to  imagine  that 
one  of  the  most  delicate  and  most  necessary  of  those 
processes,  i.e.,  the  maintenance  and  regulation  of  the 
neuro- electrical  system,  could  proceed  without  deviation  in 
any  diseased  area. 

GALVANOMETRIC   TESTS   OF    OTHER   DISEASES. 

Neurasthenia  . 
To  my  mind  a  knowledge  of  the  electro-pathology  of 
this  disease  is  of  vital  importance  to  humanity,  as,  so  far, 
it  is  imperfectly  understood  and,  therefore,  imperfectly 
dealt  with.  Neurasthenia,  of  course,  means  nervous 
weakness,  but  viewed  from  an  electro-pathological  stand- 
point it  has  a  characteristic  which  differentiates  it  from 
any  other  irregularity  of  the  nervous  system  with  which  I 
am  acquainted,  and  which  I  believe  to  be  peculiar  to  a  new 
disease.  It  certainly  has  one  feature  in  common  with 
nervous  weakness,  and  that  is  a  deficiency  of  nerve- 
energy  ;  but  while  asthenia  exhibits  a  low  hand-to-hand 
deflection,  it  is  constant,  whereas  the  neurasthenic  deflec- 
tion is  so  variable  as  to  sign  of  current  that  the  light  is 
never  at  rest.  It  may  be  anything  from  5  to  90  mm.  or 
so,  but  will  be  both  positive  and  negative,  moving  slowly 
and  erratically  backwards  and  forwards,  from  one  side  of 


ANIMAL   AND   VEGETABLE  261 

zero  to  the  other,  never  becoming  constant  or  giving  any 
definite  indication  of  the  normal  electrical  sign  of  the 
patient.  This  irregularity,  this  fluctuation,  combined  with 
an  insufficiency  of  nerve  energy,  is  a  peculiarity  of  neuras- 
thenia, distinguishing  it  from  other  nervous  affections. 

The  behaviour  of  the  sufferer  from  this  disorder  is,  as 
a  rule,  consistent  with  the  galvanometric  reading.  There 
is  a  corresponding  fluctuation  of  will.  Victims  to  neuras- 
thenia are  slow  to  admit  to  others  that  there  is  anything 
wrong  with  them,  and  if  treated  will  not  long  submit  to 
the  same  treatment,  but  go  from  doctor  to  doctor,  or  try 
a  few  doses  of  every  quack  medicine  they  see.  They  never 
seem  to  know  their  own  minds  for  many  minutes  together, 
and  in  this  respect  their  mental  and  neuro-electrical 
symptoms  appear  to  be  in  accord.  They  may,  reasonably, 
be  termed  neurotic,  but  this  is  perhaps  a  misnomer.  The 
fault,  theoretically,  can  be  said  to  be  partly  due  to  intermit- 
tent contact  between  efferent  and  afferent  centres  and 
consequent  disturbance  of  neuro-electrical  equilibrium,  in- 
volving defective  distribution  of  nerve-energy. 

Epilepsy. 

It  follows,  as  a  matter  of  course,  that  anyone  engaged  in 
electro-pathological  research  would  bestow  a  maximum  of 
attention  upon  this  awful  scourge  of  humanity,  and  I  have 
been  fortunate  enough  to  have  had  many  opportunities  of 
studying  it.  My  observations,  however,  are  strictly  con- 
fined to  the  neuro-electrical  problem  presented  by  the 
disorder,  and  even  from  this  comparatively  narrow  point 
of  view  it  exhibits  so  many  complex  features  that  I  am  quite 
at  a  loss  for  a  well-grounded  opinion  of  its  origin,  or  of  the 
predisposing  cause  or  causes.  I  know  what  happens,  but 
how  or  why  it  happens  is  hidden  from  me,  though  it  will 
certainly  be  revealed  to  some  other  student.  In  this 
connection  it  is  my  earnest  hope  that  such  data  as  I  am  able 
to  offer  may  prove  to  be  of  value. 


262      STUDIES  IN  ELECTRO-PHYSIOLOGY: 

The  principal  neuro-electrical  phenomena  common  to 
grand-mal  are  low  body  deflections,  combined  with  sub- 
normal body  temperature,  excessively  high  head  deflec- 
tions and  temperature,  and  a  point  of  least  resistance  at 
some  part  of  the  skull,  from  which,  during  an  aura  or  during 
and  directly  after  a  fit,  an  abnormally  high  deflection  is 
obtained. 

The  direct  cause  of  the  fit  is,  in  fact,  a  species  of  neuro- 
electrical  brain-storm,  and  this  storm  is  unquestionably 
due  to  the  nerve-force  supplied  to  the  brain  not  being  able 
to  find  its  proper  outlets  or  channels  from  the  brain  to  the 
nervous  system — the  afferent  nerves,  conductive  from, 
without  but  not  receptive  from  within,  possibly  adding  to 
the  pressure — with  the  inevitable  consequence  that  the 
pressure  in  the  brain  becomes  unbearable,  and  produces  a 
fit.  Were  this  pressure  not  relieved,  death  or  insanity 
would  probably  ensue,  but  Nature  provides  for  this  con- 
tingency by  creating  in  the  skull  a  path  of  least  resistance 
to  the  passage  of  the  pent-up  current  to  air.  The  exact 
spot  must  be  tested  for  and  located  in  each  case,  and  it  is 
from  this  spot — a  safety-valve — that  the  highest  head 
deflection  is  obtained. 

Too  much  importance  can  hardly  be  attached  to  the 
existence  of  this  "  safety-valve,"  because  it  not  only  points 
to  a  means  of  alleviation,  but  affords  convincing  proof  of 
the  soundness  of  the  theory  I  have  advanced. 

If  the  hair  covering  the  "  safety-valve  "  is  shaved  off 
and  a  small  silver  plate  is  fastened  upon  it  (the  valve)  by 
means,  say,  of  adhesive  plaster,  and  an  elastic  belt  carrying 
a  circular  metallic  plate,  provided  with  a  terminal,  is  placed 
round  the  waist  in  such  manner  that  the  body-plate  makes 
contact  with  the  skin,  preferably  2  in.  above  the  navel,  it 
is  only  necessary  to  connect  the  two  plates  by  a  wire — a 
shunt-circuit — to  bring  in  a  few  minutes  the  head  and  body 
deflections  and  temperatures  to  normal. 


ANIMAL   AND   VEGETABLE  268 

There  is  at  least  one  other  proof.  If  the  patient  is 
watched  and  an  aura  detected,  no  fit  will  ensue  if  the  head 
is  at  once  wetted  with  warm  salt  water,  to  lower  the 
resistance  of  the  scalp  and  create  an  artificial  path  to  air  for 
the  congested  nerve-force. 

Whatever  the  cure  may  eventually  prove  to  be,  it  must, 
as  one  of  the  curative  measures,  have  the  effect  of  pre- 
venting the  brain  from  becoming  neuro- electrically  con- 
gested and  the  body  neuro- electrically  starved.  It  has 
only  recently  been  suggested  to  me  by  Dr.  E.  W.  Martin, 
and  I  have  had  no  opportunity  of  putting  the  hypothesis 
to  the  test,  that  a  careful  galvanometric  examination  of  the 
spinal  cord  may  disclose  such  high  resistance  in  some 
anterior  part  of  it  as  to  suggest  a  temporary  break  of 
continuity.  If  that  feature  is  exhibited  in  a  number  of 
cases  it  will  be  worth  while  to  try  to  remedy  the  condition 
— i.e.,  restore  conductivity — by  local  ionic  medication. 
That  is  a  matter  for  further  research  and  experiment.  In 
the  meantime  no  one  suspected  of  a  tendency  to  epilepsy 
should  be  permitted  the  use  of  hair  pomades  or  oils,  or, 
above  all,  of  peroxide  of  hydrogen. 

As  a  final  word  upon  this  subject  I  should  like  to 
express  my  opinion  of  the  therapeutic  value  of  the  bromides 
of  potassium  and  ammonium.  They  act  by  checking  the 
generation  of  nerve-force  in  much  the  same  way  that 
they  act  in  photography.  They  check  development 
— and  especially  mental  development — and  between  a 
choice  of  two  evils  I  do  not  know  which  is  to  be  preferred  ; 
bromide  saves  trouble  to  others,  at  the  expense  of  the 
patient. 

Cancer. 

Notwithstanding  the  fact  that  many  hundreds  of  the 
most  notable  men  of  their  day  have  devoted  and  are 
devoting  their  lives  to  the  study  of  cancer,  it  is  unfortu- 
nately true  that  the /on*  et  origo  of  the  disease  still  remain 


264      STUDIES   IN   ELECTRO-PHYSIOLOGY 

in  obscurity.  Cancer  has  yielded  nothing  to  bacteriological 
research.  Surgery  cannot  claim  that  the  knife  is  an 
infallible  cure,  because  the  surgeon  can  never  be  sure  that 
he  has  removed  the  entire  growth  ;  electro-cautery  has 
proved  to  be  merely  useful,  and  medicine  has  not  been 
able  to  provide  more  than  temporary  relief  from  pain. 
From  galvanometric  research  also  nothing  decisive  has  been 
learned,  but  I  am  encouraged  to  think  that  this  is  because 
the  opportunities  of  observation  and  study  have  been  too 
few  in  number,  and  that  the  little  we  have  gained  will  at 
all  events  stimulate  other  workers  to  renewed  investiga- 
tion upon  the  lines  I  have  ventured  to  lay  down. 

Of  cases  of  suspected  cancer  I  have  tested  many,  but  of 
cancer  certified  to  by  high  medical  authority  not  more  than 
half  a  dozen.  This,  it  may  be  thought,  does  not  warrant 
me  in  coming  to  any  definite  conclusion  as  to  the  electro- 
pathology  of  this  disease,  but  if  I  disagree  it  is  because  in 
all  those  six  cases  not  only  did  I  find  the  cancer  cells  to  be 
non-conducting,  but  my  observations  have  been  borne  out 
by  others. 

From  a  cancerous  growth,  more  especially  if  it  is  not 
deep-seated,  no  deflection  whatever  will  be  obtained, 
even  if  the  skin  be  moistened,  although  the  secondary 
deposits  may  exhibit  lines  of  acute  inflammation.  The 
only  means  of  alleviation  or  cure  suggested  by  galvano- 
metric research  do  not,  so  far,  go  beyond  restoring  con- 
ductivity to  the  deionised  cells  by  suitable  ionic  medication, 
but  the  galvanometer  should  provide  valuable  assistance 
to  the  operating  surgeon  by  enabling  an  accurate  diagram 
of  the  whole  of  the  affected  area  to  be  drawn  upon  the  skin. 
The  disease,  as  we  know,  frequently  recurs  because  com- 
plete excision  has  not  been  made. 


APPENDIX 


APPENDIX  26T 


ELECTRICAL    CONDITIONS    OF   THE    EARTH 

In  the  first  section  of  this  work  I  have  said  that  in 
countries  free  from  magnetic  and  seismic  disturbances  and 
in  ordinary  conditions  of  weather  the  earth  is  the  negative 
terminal  of  Nature's  electrical  system.  That  is  a  state- 
ment of  fact,  but  modernity  has,  in  some  of  the  large  towns 
of  the  world,  introduced  a  new  factor  in  a  multiplicity  of 
electrical  railways  and  "tubes,"  and  this  factor  must  be 
considered  in  relation  to  the  accepted  theorj/^  that,  as 
compared  with  all  other  electrical  tensions,  the  earth  is 
regarded  as  zero. 

In  body-testing  it  is  necessary  that  it  should  be, 
approximately,  so.  There  must  always  be  a  transfer 
from  a  plus  to  a  minus  quantity  vvhen  there  is  direct 
conduction.  If  the  transfer  is  made  inductively  then  the 
problem  becomes  one  of  tension  and  spark-gap. 

In  electro-diagnosis  and  body-testing  generally  the 
patient  must  be  connected  for  some  minutes  with  an 
"  earth  "  of  low  resistance  in  order  to  remove  any  possi- 
bility of  charge  from  a  source  of  energy  other  than  that  of 
the  body  itself,  and  if  this  is  to  be  accomplished  it  follows 
that  the  tension  of  the  body  must  be  plus  and  that  of  the 
earth  minus,  otherwise  there  would  be  a  transfer  of  elec- 
tricity from  the  earth  to  the  body  instead  of  from  the  body 
to  the  earth. 

In  certain  localities,  and  in  abnormal  conditions  of 
weather  in  other  localities,  the  earth  may  become  very 
highly  charged,  and  unless  this  is  taken  into  account  results 
may  be  obtained  in  testing  which  will  perplex  the  observer. 


268  APPENDIX 

In  order  to  illustrate  my  meaning  we  may  usefully 
ponder  earth  conditions  during  a  thunderstorm,  in  relation 
to  contour  and  nature  and  conductivity  of  soil. 

Let  us  disregard  for  the  moment  the  terms  positive  and 
negative  and  substitute  for  them  the  words  "  plus  "  and 
*'  minus."  \ 

The  air,  the  upper  stratum  and,  hypothetically,  stretch- 
ing upwards  to  infinity,  is  always  "  plus  "  ;  the  earth, 
normally,  "  minus." 

Between  the  charged  cloud  and  the  comparatively 
uncharged  earth  there  is  an  air-space — ^the  spark-gap — and 
unless  the  tension  of  the  cloud  is  sufficiently  high  to  bridge 
it  no  discharge  can  take  place.  Suppose  the  surface  of 
the  earth  to  be  flat — 


loud 


£arth 


Fig.  144. 


or,  alternatively,  the  surface  to  be  very  dry  or  composed  of 
some  more  or  less  dielectric  material.  The  cloud  would — 
unless  the  tension  were  extraordinarily  high — travel  over 


Fig.  145. 

such  ground  without  discharging.  When,  however,  by 
reason  of  contour,  the  distance  between  earth  and  cloud 
was  lessened  to  one  that  the  tension  of  the  cloud  could 


APPENDIX  269 

overcome,  or,  alternatively,  tension  being  sufficient,  a 
point  was  reached  where  the  soil  favoured  conduction,  a 
transfer  of  potential  from  the  plus  cloud  to  the  minus  earth 
would  at  once  take  place,  in  exactly  the  same  manner  that 
a  spark  is  obtained  from  a  Leyden  jar  or  induction  coil  when 
the  conducting  knobs  or  points  are  approached  near 
enough  to  each  other.  Scientifically  this  is  termed  a 
disruptive  discharge.  It  occurs  when  the  air  becomes 
strongly  strained  by  the  potential  difference,  and,  suddenly 
yielding,  allows  the  discharge  to  pass,  not  freely  as  through 
a  conductor,  but  by  a  violent  disturbance  of  the  molecules 
of  air  along  the  path,  which  become  strongly  heated,  and 
make  the  visible  spark.  This  takes  a  zigzag  and  forked 
path  which  in  all  probability  is  the  line  of  least  resistance, 
and  is  due  to  irregular  distribution  of  conducting  motes  in 
the  air,  or  to  its  hygrometrical  condition. 

However  this  may  be,  we  will  imagine  that  at  the  point 
A  (Fig.  1 46)  the  sub-soil  is  of  such  a  nature  that  the  charge 
which  it  has  just  received  from  the  cloud  cannot  be  readily 
dissipated,  and  that  another  cloud  which  has  discharged 
itself  in  the  immediate  vicinity  passes  over  it  within  a 
distance  over  which  the  spark-gap  can  be  bridged.     The 


Fig.  146. 

result  m.ust  be  that  discharge  will  take  place  from  earth  to 
cloud,  because  the  cloud  is  the  minus  and  the  earth  the 
plus  quantity  ;  but  it  does  not  necessarily  follow  that  such 
discharge  must  be  from  the  exact  area  which  first  received 


270  APPENDIX 

it ;    it  is  only  required  that  the  plus  and  minus  quantities 
should  be  earth  and  cloud  respectively. 

In  the  same  way  the  human  body  is  liable  to  be  in- 
fluenced not  only  by  being  placed  in  an  earth  circuit  but  by 
induction  ;  its  normal  electromotive  force  of  four  or  five 
millivolts  can  only  be  a  plus  quantity  in  favourable 
circumstances. 

In  reviewing  the  electrical  phenomena  consequent  upon 
the  operation  of  such  a  system  as  the  District  Railway,  we 
may  read  for  electrified  clouds  the  effect  upon  the  air  of 
alterations  of  load,  while  the  iron-clad  tubes  with  their  far 
from  perfect  insulation  must  be  responsible  for  artificial 
earth-currents  of  such  potential  as  to  seriously  interfere, 
over  a  very  considerable  area,  with  electro-diagnosis. 

Similarly  in  tramway  lines  where  direct  current  is 
employed  the  overhead  system  is  likely  to  affect  the  air 
locally,  and  the  conduit  system  to  charge  the  earth,  although 
the  range  of  inductive  interference  is  not  nearly  so  great  as 
in  the  case  of  railways  and  tubes. 

Quite  apart  from  these  artificial  disturbances,  the 
hypothesis  that  in  an  electrical  sense  the  earth  is  zero 
should  not  be  too  readily  accepted.  Prior  to  important 
experiment  an  "  earth  "  should  be  tested  galvanometrically, 
and  although  in  certain  localities  the  test  may  be  dispensed 
with  in  ordinary  work,  it  is  a  precaution  to  be  recom- 
mended. 

As  a  matter  of  fact  the  earth  is  electrically  "  patchy," 
the  potential  and  direction  of  current  varying  greatly  in 
different  parts  of  the  world.  Darwin  found  the  neighbour- 
hood of  the  Rio  Plata  to  be  peculiarly  subject  to  electrical 
phenomena  and  was  inclined  to  suspect  that  thunder- 
storms were  very  common  near  the  mouths  of  great  rivers.* 
On  the  East  African  coast  the  earth-current  has  remained 
at  about  forty  volts  for  many  weeks  in  succession.  At  that 
*  Journal  of  Researches. 


APPENDIX  271 

time  I  was  stationed  at  Delagoa  Bay,  where  the  English, 
Temb^,  Umvelosi,  and  other  rivers  debouch.  Thunder- 
storms during  the  rainy  season  were  of  very  frequent 
occurrence.  Durban,  some  360  miles  south,  is  situate  at 
the  mouth  of  the  Umgeni  river,  and  in  the  same  season  is 
visited  by  a  thunderstorm  almost  every  afternoon  at  about 
the  same  hour.  We  are  aware  that  such  storms  occur  most 
frequently  within  the  tropics  and  diminish  in  frequency 
towards  the  poles,  during  day  rather  than  night,  after 
midday  than  before  it,  and  in  mountainous  countries  than 
in  plains,  but  we  have  no  definite  knowledge  of  the  causes 
•which  set  up  and  set  in  motion  the  forces  known  to  us  as 
natural  earth-currents. 

Flammarion  attributes  the  aurora  borealis,  which 
sometimes  illumines  the  darkness  of  night  in  the  Arctic 
and  other  regions  of  the  North,  to  the  striking  of  a  balance, 
silent  and  invisible,  between  two  opposing  tensions  of 
the  atmosphere  and  the  earth  ;  thus  the  apparition  of  the 
aurora  borealis  in  Sweden  or  Norway  is  accompanied  by 
electric  currents  moving  through  the  earth  to  a  distance 
sufficiently  great  to  cause  the  magnetic  needle  to  record  the 
occurrence  in  the  Paris  Observatory . 

Indeed,  the  electricity  which  pervades  the  earth  is 
identical  with  that  which  moves  in  the  heights  of  the 
enveloping  atmosphere,  and  whether  it  is  positive  or 
negative  its  essential  unity  remains  the  same,  these 
qualities  serving  only  to  indicate  a  point,  more  or  less  in 
common,  between  the  different  charges.  The  heights  of 
the  atmosphere  are  more  powerfully  electrified  than  the 
surface  of  the  globe^  and  the  degree  of  electricity  increases 
in  the  atmosphere  with  the  distance  from  the  earth. 

Atmospheric  electricity  undergoes,  like  warmth,  and 
like  atmospheric  pressure,  a  double  fluctuation,  yearly  and 
daily,  as  well  as  accidental  fluctuations  more  considerable 
than  the  daily  ones.     The  maximum  comes  between  six 


272  APPENDIX 

and  seven  in  the  morning  in  summer,  and  between  ten  and 
twelve  in  winter  ;  the  minimum  comes  between  five  and  six 
in  the  afternoon  in  summer,  and  about  three  in  the  after- 
noon in  winter.  There  is  a  second  maximum  at  sunset, 
followed  by  a  diminution  during  the  night  until  sunrise. 
(Flammarion,  1905.) 

Fulminic  matter,  remarks  the  same  author,  is  strongly 
attracted  towards  damp  regions,  and  is  guided  on  its  way 
to  the  earth  by  the  hygrometrical  conditions  of  the  atmo- 
sphere. Violet  lightning  is  thought  to  come  from  the 
upper  stratum  of  the  atmosphere,  and  a  flash  has  been 
found  to  have  a  maximum  length,  as  observed  from  the 
earth,  of  over  eleven  miles. 

That  earth-currents  have,  at  times,  an  origin  which  is 
in  part  thermal  seems  not  unlikely.  Earthquakes  are  of 
common  occurrence  in  the  tropics,  and  I  remember  two 
on  the  East  Coast  of  Africa.  One  made  a  difference  of 
750  fathoms  in  the  soundings  off  Mozambique,  and  the 
other  was  experienced  at  Delagoa  Bay  much  about  the 
time  that  the  earth-current  rose  to  forty  volts.  It  is  a 
curious  fact,  though  probably  only  a  coincidence,  that  the 
submarine  upheaval  off  Mozambique,  the  earthquake  at 
Delagoa  Bay,  and  the  forty-volt  earth-current  before 
mentioned  took  the  same  course,  i.e.,  north  and  south. 
Dutton  records  an  instance  of  an  earthquake  at  the 
Yaqui  river  which  disturbed  the  needle  of  the  magneto- 
graph  at  Los  Angeles,  a  distance  of  more  than  six  hundred 
miles,  and  it  is  possible  that  forces  which  in  themselves 
are  insufficient  to  cause  even  a  slight  convulsion  of  Nature 
may  be  responsible  for  the  creation  of  high  potential  at  one 
point,  whence  it  is  distributed  to  another  point  or  points  of 
lower  potential ;  the  precise  path  being  governed  by  electro- 
lytes in  the  earth,  or,  in  other  words,  by  the  same  law  which 
directs  the  course  of  lightning  through  the  atmosphere. 

In    speaking    of    earthquakes    we    must,    of    courscj 


APPENDIX  278 

differentiate  between  those  which  are  caused  by  sub- 
sidences and  those  of  volcanic  origin.  Volcanoes  are  not 
confined  to  any  one  part  of  the  world,  but  are  to  be  found, 
so  far  as  latitude  is  concerned,  pretty  nearly  everywhere;  in 
the  Arctic  Ocean,  in  the  volcanic  island  of  Jan  Mayen> 
between  Iceland  and  Spitzbergen ;  there  are  Mount 
Erebus  and  Mount  Terror  in  the  Antarctic,  besides  very 
numerous  volcanoes  in  the  Atlantic,  Pacific,  and  Indian 
Oceans,  and  their  shores  in  both  the  temperate  and  torrid 
zones.  In  all  they  are  said  to  number,  in  a  state  of  activity* 
some  three  hundred.  "  Of  these  about  two  hundred  and 
fifty  lie  either  on  the  borders  of  the  Pacific,  or  on  some  of 
its  many  islands.  Thirty-nine  either  lie  v/ithin  or  on  the 
borders  of  the  Atlantic,  of  which  thirteen  are  in  Iceland, 
or  near  the  Arctic  Circle,  three  in  the  Canaries,  seven  in  the 
Mediterranean  Sea,  six  in  the  Lesser  Antilles,  and  ten  in 
the  Atlantic  Ocean  Islands.  There  are,  however,  a  much 
greater  number  of  extinct  volcanoes,  which  may  at  any 
time  again  become  active."     (Houston,  1908.) 

The  difficulty  we  are  faced  with  is  conveyed  in  the  last 
paragraph.  Were  it  not  for  the  uncertain  number  and 
condition  of  extinct  volcanoes,  or  rather  of  volcanoes 
v/hich  have  ceased  for  the  time  being  to  give  any  mani- 
festation of  activity,  we  might  consider  earth-currents  in 
their  possible  relation  to  areas  liable  to  thermal  dis- 
turbances with  a  view  to  determining  whether  any  con- 
nection between  them  is  suggested  by  their  coincidence. 

One  fact  stands  out  prominently  :  thunderstorms 
diminish  in  frequency  towards  the  poles,  and  if  they  are  a 
factor  in  determining  the  occurrence  and  strength  of  earth- 
currents  of  unusual  tension  one  would  expect  to  find  a 
minimum  of  disturbance  towards  the  poles.  I  happen  to 
know,  however,  that  in  the  neighbourhood  of  Port  Arthur 
— a  region  admittedly  volcanic — the  earth-current  some- 
times attains  a  potential  of  500  volts. 

T 


274  APPENDIX 

In  the  early  part  of  this  Appendix  I  have  spoken  of  a 
dry  or  more  or  less  dielectric  earth-surface,  and  we  may 
usefully  consider  what  its  effect  may  be  upon  health. 

The  electrical  condition  beneficial  to  plant  life  is  soil 
conductivity.  If  the  soil  is  not  moist  to  the  root-depth  the 
plant  is  deprived  of  its  supply  of  current,  and  must  suffer 
injury. 

Dr}^  earth,  if  not  a  non-conductor  of  electricity  of  high 
tension,  is  at  least  a  very  bad  conductor,  as  are  certain 
clay  and  rock  formations.  With  such  an  upper  stratum 
there  could  be  no  normal  circuit.  In  that  area  the  earth- 
terminal  would  be  insulated,  and  the  air,  I  should  imagine, 
abnormally  charged  by  reason  of  the  absence  of  a  low 
resistance  path  to  earth.  It  would  be  interesting  to  have 
some  information  upon  the  subject  of  the  health  of  persons 
residing  in  these  localities  and  the  bearing  of  climatic 
conditions  of  the  kind  upon  specified  diseases. 

At  the  same  time,  data  as  to  the  influence  upon  man  and 
plant  of  ferruginous  soils  should  be  useful  if  only  for 
piu-poses  of  comparison  ;  I  say  ferruginous,  because  with 
iron  as  the  electrolyte  it  is  possible  to  have  dry  air  and 
earth  and,  at  the  same  time,  good  earth-conductivity, 
whereas  in  swampy  districts  there  would,  quite  apart  from 
miasma,  etc.,  be  a  damp  atmosphere  and  therefore  a 
totally  different  environment. 

In  the  analysis  of  climate  in  its  relation  to  disease  many 
painstaking  investigators  have  confined  themselves  to 
pondering  characteristics  of  the  atmosphere,  and  with 
those  we  have  no  present  concern,  except  in  so  far  as  they 
may  be  affected  by  the  electrical  receptivity  or  otherwise 
of  the  earth.  It  is  true  that  dust  from  dry  soil  may 
contain  the  germs  of  infectious  diseases  and  aggravate 
affections  of  the  respiratory  organs,  but,  difficult  as  it  is, 
I  want  to  ascertain  the  effect  of  a  non-conductive  as 
opposed  to  a  conductive  dry  soil  upon    certain  specified 


APPENDIX  275 

diseases.  In  the  tropics  death-rates  are  high,  but  bad 
sanitary  conditions  and  lack  of  medical  attendance  account 
to  some  extent  for  mortality  among  the  natives,  while  an 
irrational  mode  of  life  explains  many  deaths  among  persons 
coming  from  cooler  climates.  Generally  speaking,  malarial 
and  yellow  fever  are  only  endemic  on  coasts  and  in  the 
neighbourhood  of  waterways,  and  only  then  when  the  air 
temperature  is  75°  F.  or  over  and  the  earth  sodden.  In 
such  case  there  would  be  an  upper  earth-stratum  of  un- 
usually low  resistance,  and  the  air-charge  might  be  at  its 
minimum,  with  consequent  loss  of  part  of  its  value  as  a 
vitalising  agent.  Stations  more  than  a  few  hundred  or 
thousand  feet  above  the  sea-level  are  free  from  yellow 
fever,  probably  because  of  their  lower  temperatures 
increased  earth-resistance,  and  higher  air-potential. 
Yellow  fever  has  only  very  rarely  occurred  at  an  altitude 
of  4,000  ft.  above  sea-level,  and  the  same  remarks  appear 
to  apply  to  dysentery  and  diarrhoeal  disorders,  as  well  as  to 
many  other  diseases  of  which  the  predisposing  cause  is 
lowered  vitality. 

Dengue  fever  is  distinctly  a  disease  of  warm  climates, 
and  is  always  checked  by  cold  weather  ;  it  follows  coast- 
lines, deltas,  and  large  river -valleys.  In  beri-beri  high 
temperature  and  dampness  are  controlling  factors,  as  is  the 
case  in  sleeping  sickness  and  yaws.  In  the  tropics  "  the 
drier  districts  are  to  be  preferred  to  the  moister,  the  higher 
altitudes  to  the  lowlands."     (Ward,  1908.) 

Temperate  zones  may  be  said  to  be  intermediate 
between  the  equatorial  and  polar  zones.  Here  we  have 
variations  of  temperature  and  moisture  which,  so  far  as 
their  influence  upon  health  is  concerned,  are  beyond  our 
purview,  inasmuch  as  there  are  many  conflicting  theories 
and  no  really  conclusive  evidence,  apart  from  the  broad 
fact  that  in  tuberculosis  and  other  and  similar  diseases 
the  dry,  pure  air  and  abundant  sunshine  of  many  of  the 


2T6  APPENDIX 

well-known  mountain  resorts  are  very  favourable  climatic 
helps.  In  this  connection,  however,  one  cannot  tell  how 
far  purity  of  air,  hygienic  surroundings,  and  a  suitable 
dietary  may  counteract  upon  an  unfavourable  earth 
condition.  We  can  only  be  sure  that  a  lowered  vitality 
not  only  predisposes  to  disease  but  operates  against  its 
cure. 

In  the  polar  regions  larger  temperature  ranges  can  be 
endured  in  the  winter,  when  the  air  is  dry.  In  severe  cold 
the  vitality  of  the  body  is  lowered  and  the  ability  to  bear 
hardships  decreased.  But  here,  again,  the  body  is  acted 
upon  directly  by  cold.  The  resistance  of  the  natural  (semi- 
liquid)  conductors  is  increased,  the  blood  circulates  more 
slowly,  the  surface  blood-vessels  contract,  and  only  an 
added  skin-resistance,  by  helping  to  conserve  energy, 
prevents  the  heart  and  lungs  from  becoming  dangerously 
affected.  Eskimos  are  protected  against  the  cold  by  their 
thick,  fatty  tissues,  which  give  them  high  absolute - 
insulation. 

It  is  a  complex  subject.  "  Diseases  usually  charac- 
teristic of  one  zone  are  known  to  spread  widely  over  other 
zones.  Diseases  which  usually  prefer  the  warmer  months 
sometimes  occur  in  the  coldest.  Rules,  previously  deter- 
mined as  the  result  of  careful  investigation,  often  break 
down  in  the  most  perplexing  way.  Some  of  the  difficulty 
in  this  lack  of  agreement  results  from  untrustworthy 
statistics,  often  collected  under  varying  conditions  and 
really  not  comparable.  Curves  are  smoothed  to  such  an 
extent  that  they  can  be  made  to  show^  anything.  Con- 
clusions are  drawn  in  individual  cases  which  are  neither  of 
general  application,  nor  do  they  even  apply  locally  on  any 
other  occasion  than  the  special  one  in  question.  Most  of 
this  disagreement  comes  from  the  fact  that  not  only  may 
the  different  weather  elements  themselves,  temperature, 
moisture,    v^dnd,    sunshine,    and   so    on,    each   have   some 


APPENDIX  277 

effect  in  the  production  of  a  disease  which  it  is  impossible 
to  determine,  but  so  many  factors  are  concerned  in  the 
matter  that  confusion  and  contradiction  in  the  conclusions 
reached  are  inevitable."     (Ward,  1908.) 

All  this  is  very  interesting  and  true,  but  it  does  not 
answer  my  question  as  to  the  relative  effect,  if  any,  of 
non-conducting  and  conducting  soils — other  things  being 
equal — upon  certain  specified  diseases,  and  I  am  afraid  that ^ 
so  far,  nothing  of  value  upon  this  subject  has  been  pub- 
lished, probably  not  even  recorded. 

This  much,  however,  is  known  to  a  few  submarine 
cable  electricians.  A  simultaneous  observation  taken  at 
eighteen  stations  in  1912,  and  my  own  results  during  this 
year,  gave  the  maximum  earth-current  as  eight  volts,  and 
this  can,  in  all  probability,  be  accepted  as  the  normal  maxi- 
mum, for  fairly  ^hort  cables,  in  the  absence  of  magnetic 
disturbances.  Long  cables,  on  the  other  hand,  not  infre- 
quently exhibit  currents  of  comparatively  high  tension, 
and  this  may  be  explained  by  the  greater  area  traversed 
by  them. 

ELECTRICITY   IN   RELATION   TO   SOME 
VEGETABLE   POISONS. 

I  have  read  recently  of  persons  being  poisoned  by 
rhubarb  leaves,  boiled  and  eaten  as  a  vegetable.  My 
research  work  has  taught  me  what  to  avoid  in  vegetarian 
diet,  although  I  am  not  a  vegetarian,  and  we — my 
people  and  I — have  enjoyed  rhubarb  leaves  for  years. 
They  are,  however,  always  more  or  less  aperient,  and 
should  be  eaten  in  moderation. 

The  subject  of  vegetable-poisoning  in  relation  to 
dietary  and  habit  is  one  of  interest  and  importance,  and  I 
am  glad  to  be  able  to  throw  some  light  upon  it. 

All  vegetable  toxins,  so  far  as  my  experiments  have 


278  APPENDIX 

gone,  yield  a  negative  galvanometric  reaction.  The 
negative  system  of  a  plant  is  in  the  root,  stem,  stalks,  and 
veins  of  the  leaves.  The  older  the  leaves  are — and  as  a 
rule  they  are  those  nearest  the  soil — ^the  larger  the  veins. 
This  argues  lower  internal  resistance,  and  therefore  more 
current,  with,  as  I  have  found,  greater  toxic  activity.  In 
all  probability  only  the  areolae  of  the  leaves  approach 
chemical  neutrality. 

As  instances  of  this  we  may  take  the  tobacco  and  tea 
plants.  In  the  former  the  lower  leaves  are  coarse- veined, 
and  contain  so  much  essential  oil  as  to  be  fit  only  for  the 
manufacture  of  insecticides,  while  everyone  knows  that, 
given  any  description  of  tea,  the  choicest  of  it  will  be  the 
young  tips  and  flowers,  owing  mainly  to  their  comparative 
freedom  from  tannic  acid. 

The  stalk  and  veins  of  the  leaves  of  many  plants  and 
vegetables  are,  no  doubt,  harmless,  but  even  when  Nature 
does  not  render  them  unpalatable  instinct  teaches  us  to 
reject  them.  If  the  stalks  of  the  cabbage  are  not  unpleasant 
of  taste  they  are  hard  and  somewhat  fibrous  ;  so,  too,  the 
core  of  the  apple,  the  white  negative  substance  in  the 
orange,  and  the  root  of  the  lettuce,  are  bitter,  and  so  on, 
through  a  wide  range  of  the  vegetable  tribes. 

I  have  no  information  upon  the  subject,  but  venture  to 
express  the  opinion  that  vegetable  poisons  will  be  found 
only  in  those  parts  of  a  plant  which  yield  a  negative 
galvanometric  deflection. 

In  any  case  it  should  be  of  advantage  to  remove  the 
larger  veins  by  excision  from  all  leaves  used  for  food.  The 
difference  in  flavour  is  very  marked  when  this  is  done,  and 
will  more  than  repay  the  trouble  taken. 

A  simple  experiment  will  demonstrate  this  very 
effectively.  Take,  say,  J  lb.  of  any  kind  of  tea.  From 
2  oz.  of  this  pick  out  and  throw  away  all  the  loose  stalks, 
of  which  there   are  generally   many.     Then   prepare  an 


APPENDIX  279 

infusion  from  each  sample  and  compare.  In  the  same 
way  whole  leaves  of  tobacco  may  be  treated  by  cutting 
away  as  far  as  possible  all  the  veins,  and  the  residue  smoked 
in  a  pipe.  This  will  be  pronounced  infinitely  superior  to 
the  crumpled  untreated  leaf. 


280  BIBLIOGRAPHY 


BIBLIOGRAPHY 

Physiology  of  Plants  :  Sachs. 

Text-book  of  Biology  :  Davis. 

Vegetable  Physiology  :  Carpenter. 

Physiology  of  Plants  :  Darwin  and  Acton. 

Microscopic  Fungi  :  Cooke. 

Structural  and  Physiological  Botany  :  Thome. 

Plant  Life  and  Structure  :  Dennert. 

Evolution  of  Plant  Life  :  Massee. 

Agricultural  Botany  :  Potter. 

The  Evolution  of  Plants  :  Scott. 

Plant  Life  on  Land  :  Bower. 

Handbook  of  Plant  Form  :  Clark. 

Text-book  of  Botany  :  Vines. 

Vegetable  Physiology  :  Green. 

Text-book  of  Botany  :  Strasburgeb  and  others. 

Chemistry  of  Plant  and  Animal  Life  ;  Snyder. 

The  Vegetable  World  :  Figuier. 

Botanical  Text-book  :  Gray. 

The  Food  of  Plants  :  Grundy. 

Descriptive  and  Physiological  Botany  :  Henslow. 

Botany  :  Sir  J.  D.  Hooker. 

Agricultural  Botany  :  Percival. 

Handbook  of  Physiology  :  Halliburton,  1915. 

Manual  of  Physiology  :  G.  N,  Stewart. 

Essentials  of  Human  Physiology  :  Noel  Paton. 

Essentials  of  Histology  :  Schafer. 

Text-book  of  Human  Physiology  :  Landois  and  Stirling. 

Physiology  :  Thornton. 

Animal  Physiology  :  Cleland. 

The  Central  Nervous  System  :  Binger-Hall. 

Physiology  of  Muscles  and  Nerves  :  Rosenthal. 

Animal  Physiology  :  Carpenter. 

Manual  of  Human  Physiology  :  Hill. 

The  Human  Species  :  Hopf. 

The  Evolution  of  Man  :  Haeckel. 

Text-book  of  General  Pathology  :  Thoma. 

Origin  of  Species  :  Darwin. 

The  Evolution  of  Forces  :  Le  Bon. 

Method  and  Results  :  Huxley. 

Text-book  of  Electro -Chemistry  :  Arrhenius. 


BIBLIOGRAPHY  281 

The  Wonders  of  Life  :  Haeckel. 

Effects  of  High  Explosives  upon  the  Central  Nervotts  System  :  Mott. 

The  Evolution  of  Sex  :  Geddes  and  Thomson. 

Evolution  :  Geddes  and  Thomson. 

The  Coming  of  Evolution  :  Judd. 

The  Evolution  of  Life  :  Bastian. 

Transformations  of  the  Animal  World  :  Deperet. 

Consolation  in  Travel :  Sir  Humphry  Davy. 

The  Signs  of  Life  :  Waller. 

Evolution  of  Living  Purposive  Matter.     1910.     Macnamaha. 

Medical  and  Surgical  Use  of  Electricity  :  J3eard  and  Rockv>  ei,j. 

Telegraphy  :  Preece  and  Siveavhight. 

Submarine  Cable  Testing  :  Baines. 

Th'  I'Jiher  of  Space  :  Sir  Oliver  Lodge. 

Electricity  and  lilagnelisni  :  Gordon. 

Telcgraj}hy  :  Herbert. 

Various  Forces  in  Nature  :  Faraday. 

Electricity  :  Gumming. 

Electricity  :  Ferguson. 

Modern  Electrical  Theorij  :  Campbell. 

Organic  Chemistry  :  Remsen. 

2'he  Science  of  Light :  Phillips. 

Journal  of  Researches  :  Darwin. 

Meteorology  :  Buchan. 

The  Story  of  the  Heavens  :  Sir  R  .  Ball. 

Thunder  and  Lightning  :  Flammarion. 

Earthquakes  :  Dutton. 

Physical  Description  of  the  Earth  :  Humboldt. 

Volcanoes  and  Earthquakes  :  Houston. 

Climate,  considered  in  Relation  to  Man  :  Ward, 


INDEX 


288 


INDEX 


Absolute  insulation  in  vegetable 
life,  10  et  seq.,  20,  133 

Achromatic  fibres,  104 

„  spindle,  103,  111 

Acorn,  the,  32 

Adams,  218 

Aerobic  micro-organisms,  113 

Agriculture  and  high-tension  elec- 
tricity, 42 

Air  as  normal  "  earth,"  55,  146,  206 
„  ,  sign  of,  7 

Albumins  of  plants,  158 
„         „  man,  158 

Aldini,  51 

Allium  odorum,  118 

Amides,  132 

Amoeba,  the,  107,  140 
„       and  stimuli,  139 

Amoeboid  movement,   114,   138,  ei 
seq. 

Ampere,  experiments  of,  141,  189 

Anaerobic  micro-organisms,  113 

Anderson,  xxvi 

Animal  electricity,  50 
„       magnetism,  116 
„      tissues,  resistance  of,  79 
„       and  vegetable  cells,  5 

Anterior  cornu,  216 

Anthyllis  Vulneraria,  45 

Apple,  the,  10,  19,  36 

,,     ,  absolute  insulation  of,  10 

Arborisations,    98,    168,    171,    172, 
207, 210, 215 

Areolae,  44 

Arrhenius,  73,  142,  250 

Artichoke,  Jerusalem,  15,  16 

Artificial  multipolar  cell,  206  et  seq. 
„  muscular  fibre,  150 

Ascaris  megalocephala,  110 

Asclepias,  127 

Asexual  reproduction,  112 

Asthenia,  260 

Athoea  rosea,  pollen  cells,  122 

Atmospheric  electricity,  271,  275 

Attraction  sphere,  103,  104,  108 

Auditory  meatus,  228  et  seq. 
„         nerve,  227  et  seq. 


Aurora  borealis,  271 

Automatic  system,  182 

Autonomic  ganglia,  202 

Axis  cylinder,  165,   168,   192,  195, 

204,  207,  210 
Axon,  168,  190,  204,  212 

B 

Bacteria,  113 
Baines,  F.  E.,  xxv 

„     ,  G.  M.,  94 
Bamboo,  node  of,  193 
Banana,  the,  10,  20 
Bar  magnets,  117 
Barcelona  nut,  32 
Basilar  membrane,  231 
Bayliss,  85 
Beard,  49 

Begonia,  experiment  \vith,  159 
Bell,  218 
Bennett,  3 
Berzelius,  217 
Bipolar  cells,  201,  205,  216 
Blastoderm,  formation  of,  122 
Body  temperature,  252 
Bone  connection  with  muscle,  172 

et  seq. 
Bone,  temporal,  228 
Bose,  158 
Bromides,  263 
Brucke,  156 


Cabbage,  the,  278 

Cajal,  168 

Cancer,  244,  263 

Capacity  in  vegetable  life,  17  et  seq. 

,,        of  human  body,  54,  57,  79, 
81,  82,  98,  99,  184,  213 
Capacity  of  liquids,  57  et  seq. 

„        in  telegraphy,  91  et  seq. 

„        test,  101  et  seq. 
Capillary  vessels  of  lung,  126 
Carbon  disulphide,  217 

rod, 231 
Cardiac  muscle,  99,  182,  183 
Cardiograms,  68,  201 


284 


INDEX 


Carrot,  the,  13 
Cartilage  cells,  122 
Catarrh  of  middle  ear,  233 
Causes  contributing  to  error,  54 
Cells,  artificial,  206  ei  seq. 

„   ,  bipolar,  201 

„  ,  multipolar,  198 

„  ,  nerve,  203  et  seq. 

„  ,  neuroglia,  203 

„  ,  pigment,  221 

„     of  Purkinje,  168 

,,   ,  storage,  200 

,,   ,  unipolar,  201 
Cell  protoplasm,  138 

,,    reproduction,  103  ei  seq.,  117 
Centriole,  the,  103,  106 
Centrosome,  the,  103,  106,  108,  109 
Centrospheres,   114 
Cerebellum,  168 
Changing  sign  of  impiilse,  151,  207, 

212 
Chemical  processes  vmhin  cells,  3 
Chlorosis  in  plants,  43,  158 
Cholesterol,  100 
Choroid,  221  et  seq. 
Chromatin,  114 

Chromoplasm  filaments,  103,  108 
Chromosomes,  103,  110 
Chunder  Bose,  158 
Circulation  in  foetus,  22,  84 
Clausius,  142 
Climate  and  disease,  274 
Cob  nuts,  83  et  seq. 
Cochlea,  the,  229,  231 
Colour  in  seeds,  31  et  seq. 
Comparative  insulations,  55 
Condenser,  construction  of,  91 

,,         ,  how  shown,  171" 
Condensers  in  parallel  and  series, 

93  et  seq. 
Conditions  of  the  earth,  267  et  seq. 
Conducting  layer  of  seeds,  23  et  seq. 
Conduction   affected   by  heat,   74, 

246,  252 
Conduction  of  stimuli  in  plants,  130, 

131 
Conductivity,  impaired,  258 

,,  of  air,  55 

Cones  and  rods,  221,  222  et  seq. 
Connective  tissue,  87,  168,  172,  187, 

204 
Connection  of  muscles  and  bones, 

172  et  seq. 
Constancy  of  vegetable  cells,  37 
Constrictions  of  Ranvier,  195 
Contraction  of  muscle,   52,   147  et 

seq.,  159 
Convection,  56 
Cenveyance  of  colour,  220 


Copper  taping  of  wires,  163,  164 
Corpus  striatum,  216 
Cucumber,  11 

Cucurbita  pepo,  cells  from,  125 
Curara  and  motor  nerves,  158 
Current,  sign  of,  244 
Cytoplasm,  Hi 
Czapec,  142 

D 

Darwin,  5,  270 

Daughter  nucleus,  104  et  seq.,  109 

Davis,  39,  112,  157 

Da^'y,  141 

Dead  muscle,  155,  159 

Deafness,  nei-vous,  230 

Deflections  given  by  vegetables,  9, 59 

Deflection  of  light  rays,  220 

Dendrons  and  synapses,  74,  76,  78, 

168,  203,  212,  213 
Dengue  fever,  275 
Diaster,  in  mitosis,  104 
Diatomaceae,  112 
Dielectric,  146 

„        ,  effect  of  heat  upon,  251 
„         treatment,  259 
Differences  of  level,  256  et  seq. 
Differentiated  nerves,  130 
Diffusion,  89,  109 

,,      ,  effect  of  upon  vegetables, 

9 
Dioncea,  reaction  of  to  contact,  128, 

158 
Dionoea,  digestive  secretions  of,  120 
Disease  in  general,  260 
Division  of  cells,  103  et  seq.,  117 
Dobie's  line,  145,  151 
Drosera,  digestive  secretions  of,  129 
Du  Bois-Reymond,  51,  152,  156 

E 

Eak,  the,  217,  228  et  seq. 

„  ,  faults  in,  232 
Earth,  conductivity  of,  6,  7,  38,  43, 

274 
Earth,  electrical  conditions  of,  267, 

et  seq. 
Earth  connection,  242 

,,       ciu'rents,  270  et  seq. 

,,     ,  sign  of,  7 
Earthquakes,  272 
Edible  chestnut,  27  et  seq. 

„     parts  of  vegetables,  6 
Effect  of  electrical  stimulation  of 

plants,  39,  40 
Elastic  tissue,  87 
Elastin,  207 
Electrical  aspect  of  seeds,  22  et  seq. 


INDEX 


285 


Electrical  disturbances  in  plants,  4 

et  scq. 
Electrical  conditions  of  the  earth, 

267 
Electrical  equilibrium,  109 
,,  laws,  146 

,,         particles,  90 
,,  stimulation  of  plants.  39, 

-iO 
Electrical    stimulation    of    muscles 

and  nerves,  178  et  seq. 
Electrical  stimulus  of   nerves,   75, 

107,  178 
Electrical  tensions  between  air  and 

earth,  5 
Electrical  units,  245 
Electricity,  atmospheric,  271 
„  in  agriculture,  42 

,,  in  relation  to  vegetable 

poisons,  277 
Electricity,  molecular  theory  of,  1 69 
Electrodes,  theories  concerning,  8, 

52,  59  ei  seq.,  08 
Electrodes  and  electrolvsis,  20,  35, 

36,  242,  244 
Electrodes,  reliability  of,  60  et  seq. 
„         ,  thumb  pressure  on,  69 
,  the,  242-4 
Electro-cardiograms,  68,  201 
Electro-diagnosis,  234  et  seq. 
Electro-magnetic  waves,  226 
Electromotive  force  of  vegetables. 

37 
Electromotive  mechanism  in  plants, 

4 
Electrons,  vibrations  of,  220 
Electro-physiology    of    the    motor 

apparatus,  144  et  seq. 
Elodea,  cells  from,  134 
End-plates,    150,    165,     168,    179, 

180,  207,  210 
Endol>-mph,  229 
Endoneurium,  76,  162 
Endothelium    of    a    serous    mem- 
brane, 125 
Energj',  sou.rce  of  body,  85 
„      ,  storage  of,  87 
,,      ,  conveyance  of,  89 
Engelmann,  228 
Enzj-me  action,  113,  132 
Epineurium,  163 
Epilepsy,  259,  261 

,,       ,  safety-valve  in,  262 
Epiphvsis,  173 

Epithelium  cells,  118,  124,  222,  229 
Equatorial  plane,  115 
Equilibrium,  67,  105,  109,  196,  200, 

252,  261 
Error,  factors  of,  53 

„     ,  causes  contributing  to,  54,  58 


Euphorbia,  127 
Eustachian  tube,  229 
Evidences  of  the  law,  ]  1 8  c/  seq. 
Evolution,  theory  of,  5 
Excessive  nervousness,  259 
Excised  muscle,  58,  155,  159 
Excitability,  154,  156  et  seq.,  179 
Exoplasm,'l0(3,  109 
Eye,  the,  217  et  seq. 
,\     ,  artificial,  218 

F 

Faraday,  142,  146,  168 

Fats  in  animals  and  plants,   132, 

247,  256 
Fatty  acids,  133 
"  Faults  "  in  the  ears,  232 

„         ,  various,  259 
Fenestra  ovaiis,  229,  23i 

„         rotunda,  229 
Ferro-sulphate  as  an  electrolyte,  38 
Ferruginous  soils,  274 
Fertilisation  of  the  ovum,  110,  119 
Fever,  dengue,  275 

,,     ,  malarial,  275 

,,     ,  yellow,  275 
Fibres  of  Purkinje,  99 
Fibrils  of  nerve-fibre,  121 
Fibro-cartilage  cells,  123 
Fibrous  tissue,  87 
Fick,-155 
Finger-tips,  8S 
Finlay,  xxv,  xx\'ii 
Flammarion,  271 
Foetus,  circulation  of,  22,  84 

,,     ,  the  developing,  88 
Fovea  centralis,  221 
Frey,  126 
Fucus,  112 
i^uscin,  228 


Galvani,  50 

Galvanometer  connecting  wires,  242 

„        ,  D'Arsonvai,  18.  238 

„        ,  Kelvin,  7,  54,  234  ei 
seq. 

„         lamp,  241 

„         scale,  239 

„         short-circuit  keys,  241 

,,         string,  68 

,,         ,  importance  of,  259 

,,  •       and    psychological    in- 
fluence, 68 
Galvanometric  diagnosis,  244,  246, 

247 
Ganglia,  autonomic,  202 
Ganglion  cells,  120,  196  et  seq.,  216 


286 


INDEX 


Gas  gangrene.  159 

Gaskell,  125 

Gasserion  ganglion,  215 

Gastrocnemius  of  frog,  98 

Geddes,  117 

Generating  station  of  the  body,  82 

Generation  of  ner\'e-force,  84  et  seq., 

183 
Glandular  organs  in  plants,  129 
Golgi,  166,  203 
Gordon,  224 
Grape-fruit,  12 
Green,  4,  128,  129,  135 
Gro\^i;h,  stimulation  of,  7,  40 
Guard  cells,  129 
Gutta-percha,  relative  resistance  of, 

251 
GjTnnosperm,  ovule  of,  124 
GjTiostemium   of   Stylidium,   rigor 

in,  143 


H 

Hackeue,  210 

Haemoglobin,  85 

Halliburton,  73,  78,  107,  138,  142, 

161,  167,  178,  198,  203,  211.  222, 

227,  231 
Hand-to-hand "  deflection,    65,    69, 

80,  183,  231,  242,  249 
Health  in  the  tropics,  275 
Hearing,  mechanism  of,  230 
Heat,    effect   of   upon    dielectrics, 

251 
Heat,  effect    of  upon    conductors, 

252 
Hea\'iside,  7 

Hensen,  plane  of,  151,  152 
Hetero    and   homotj^ical    mitosis, 

110 
High  frequency  treatment,  42,  71 
High  tension  current  in  agriculture, 

42 
Holmgren,  205 
Hopf,  101 

Horse-chestnut,  23  et  seq. 
Hoy  a  Carnosa.  section  of,  121 
Humboldt,  50 


Incus,  229 

Induction,  140,  160,  270 

Inductive  eapacitv,  57,  91  et  seq., 

146 
Inductive  embarrassment,  160 

„         interference,     75,    162  el 

seq. 
Inhibition,  74,  77,  183 
Insomnia,  259 
Insulating  processes  of  the  body, 

161 
Insulating  system  of  seeds,  23   et 

seq. 
Insulation  of  vegetables  and  fruits, 

10  et  seq. 
Insulation  of  body  structures,  86 
Insulations,  comparative,  55 
Interstitial  protoplasm,  213 
Intra-cellular  action,  77,  113 
Involuntary    muscle,    178,    184    et 

seq.,  203"^ 
lonisation,  141 
Ions,  77,  85,  140,  142,  250 
Iris  pumila,  118 
Iron  in  body,  189,  203 

,,      as  an  electrolj'te,  42 

,,      in  plants,  43 

„      „  soil,  38,  44 
Irritable  organs  in  plants,  131,  157 
Irritability,  105,  130,  132,  143,  157, 

180 
Irritation  of  nerves,  75 


Jacket  of  vegetables,  6 

Jamieson,  xxv 

Jerusalem  artichoke,  15,  16 

K 

Kabsch,  143 
Karsten,  5 

KaryoMnesis,  114,  118,  119 
Kennelly,  xxv 
Kephalin,  100 
Kanoplasm,  114 
Kinoplasmic  spindle,  114 
Kolliker,   127 

Krause's  membrane,  100,  145,  152, 
155 


Immature  seeds,  23 

Impaired  conductivity,  258 

Impulses,  visual,  222 

Impulse,  nature  of  nerve,  73  et  seq., 

201 
Impulse,    rate    of    propagation    of 

nerve,  78,  89,  98,  213 
Impulse,   nerve,   how  transmitted, 

169 


I, 

Labyrinth,  228 

Lamina  spiralis,  229 

Landois  and  Stirling,  79,  127,  145, 

154,  160,  230 
Latex  cells,  127-134 
Laticiferous  vessels,  126,  134 
Leaf  of  horse-chestnut,  16 
„      „  ivy,  16,  17 


INDEX 


287 


Leaves,  deciduous   and  evergreen, 

16 
Le  Bon,  viii,  89,  142,  200 
Lecithin,  100 
Lemon,  the,  12 

Level,  differences  of,  256  et  seq. 
Life  of  vegetables,  36 
Light,  electro-magnetic  theory  of, 

226 
Light,  rays  of,  219  et  seq. 
Light-rays,  deflection  of,  220 
Lightning,  268  et  seq. 
Lignified  fibres  of  a  leaf,  44 
LUium  martagon,  pollen   grain   of, 

119 
Living  nerve,  resistance  of,  79 
Lobar  pneumonia,  254 
Local  action  in  fruits,  36 

„     pyrexia,  232,  244,  251,  253  et 

seq. 
Longridge,  experiments  of,  61  et  seq. 
Lycopodium,  cells  from,  123 
Lymph  space,  75,  76,  162 

M 

Macallum,  189,  203 

Macdonald,  77 

M'Gregor  Robertson,  55,  175 

Macula  lutea,  221 

Magnetic  lines  of  foi'ce,  117,  164 

Magnets,  bar,  117 

Maimbray,   42 

Malapterurus,   electrical   organ   of, 

203 
Malarial  fever,  275 
Malleus,  228 
Mangel-wurzel,  the,  12 
Martin,  vii,  63  et  seq.,  82  et  seq.,  263 
Massee,  113 
Mastoid,  232 
Matteucci,  51 
Maxwell,  73,  226,  252 
Mechanism  of  hearing,  230 
Medulla  oblongata,  215 
Medullary  sheath,  100,  121,  166 
Melanin,  228 
Membrane  of  Krause,  100,  145,  152, 

155 
Membrane  of  Reissner,  231 
Membranes  of  seeds,  23  et  seq. 
Metabolism,  127 
Mimosa  pudica,   motile  organs  of, 

143 
Mitosis,  103  et  seq.,  110,  115,  118 
Mitotic  nucleus,  105 
Molecular  movements  in  plants,  4 
,,  theory  of  electricity,  109 

Motile  organs  of  Mimosa  pudica, 

etc.,  135,  137,  143 


Motor  mechanism  in   plants,   128, 

158 
Motor  nuclei,  214 
Mott,  168,  190 
Movement  of  protoplasm  in  plants, 

135 
Mucor,  112 
Muller,  130 

Multipolar  cells,  198,  205  et  seq.,  216 
,,  cell,  artificial,  206  et  seq. 

Munk,  76 

Musele,  cardiac,  182,  184,  185 
,,        curve,  160 
,,        spindles,  210 
,,        telegraph,  152 
Muscles,    connection    with    bones, 

172  et  seq. 
Muscles,  deltoid,  174 

,,     ,  fan-shaped,  174 
,,     ,  pennate,  174 
,,     ,  semi-pennate,  174 
Muscular  contraction,   147  et  seq., 

160 
Muscular  fibre,  artificial,  150 
„  fibre-cell,  123 

,,  paralysis,  180 

,,  tissue,  144,  147  et  seq. 

Mustard  seed,  experiment  with,  38 
Myxogaster.  113 

N 

Natural  dielectrics,  89,  100 

,,        insulation  resistance,  172, 

201 
Negative  and  positive,  82 
Nerve-bundle,  section  of,  125 
Nerve  cells,  203  et  seq. 

„       centre,  definition  of,  202 

,,       conduction,  rate  of,  74,  213 

„       deafness,  230 

,,       degeneration,  179,  193 

,,      energy,  55  et  seq.,  183 

,,      energy  of  toads  and  tortoises, 

156 
Nerve  fibres  of  voluntary  muscle, 

150 
Nerve  force,  5,  6,  55,  189,  252,  256 

,,  „  ,  generation    of,  84    et 

seq.,  183 
Nerve  impulse,  nature  of,  6,  73  et 

seq.,  201 
Nerve   impulse,    how   transmitted, 

169 
Nerve  impulse,  velocity  of,  78,  227 

,,       poisoning,  158,  258 

,,       regeneration,  194 

,,     ,  resistance  of  living,  79 

„      unit,  210,  211 
Nerves,  differentiated,  130 


288 


INDEX 


Nerves,  irritation  of,  75 

of  plants,  157,  158 
,  auditory,  227  et  seq. 
,  cranial,  215 
,  hypogastric,  203 
,    motor,    147,    156,    165   ei 
seq.,  180 
Nerves,  non-mediillated,  144,  251, 

253 
Nerves,  olfactory,  222 

„      ,  optic,  130,  220  et  seq. 
„       ,  pelvic,  203 
,,      ,  peripheric,  75,  76 
„      ,  sciatic,  75 
„      ,  sensory,  194,  200,  214,  216, 
231 ,  256 
Nerves,  splanchnic,  203 
,,      ,  trigeminal,  216 
,,      ,  vagus,  182 
,,      ,  vaso-motor,  86 
„      ,  vaso-inhibitory,  86 
Nervous  breakdown,  259 

,,        energy,  183 
Neurasthenia,  260 
Neurilemma,  161,  165,  204,  251 
Neuritis,  15S,  258 
Neuro-electricity,  55  ei  seq.,  67,  107, 

204,  226,  254 
Neuroglia,  168,  171,  203 
Neuro-keratin,  100 
Neurons,  168,  171,  191,  198,  222 
Neuro-synapse,  171 
Nissl's  granules,  168,  189,  207 
Nobili,  51 

Nodes  of  Ranvier,  192  et  seq.,  204 
Noel  Paton,  147 
Noll,  5 

Non-polarisable  electrodes,  57,  58 
Non-living,  the,  120,  155 
Nuclear  disc,  115 

membrane,  109,  112,  114 
„        poles,  105,  106 
Nucleo-protein,  138 
Nucleus  and  nucleolus,  107,  108  et 

seq.,  114,  115,  189,  211 
Nutrition  or  conductivity  ?  178 
Nuts  and  seeds,  secretion  of,  26  et 

seq. 
Nux  vomica,  effect  of  upon  con- 
duction, 140,  159 

O 

Ohm's  law,  179,  198,  231,  245  ei 

seq. 
Ohm's  law  and  solutions,  250 
Oil-glands  of  the  orange,  12 
Onion,  the,  14,  18,  19,  36,  60 
Oospheres,  112,  119 
Optic  axis,  224 


Optic  nerve,  fibres  in,  220 

Ora  serrata,  222 

Orange,  the,  12,  21 

Osmosis,  10,  138 

Ovule  of  gymnosperm,  124 

Ovum,  111" 

„     ,  fertilisation  of,  119 
„     ,  segmentation  of,  110 

Oxygen,  intake  of,  43,  183 


Palms  of  the  hands,  56,  65 

Pancreas,  secretion  of,  133 

Parallelogram  of  forces,  174,  177 

Paralysis,  muscular,  180 

Parsnip,  the,  13 

Particles,  electrical,  90 

Passiflora,  sense  of  touch  of,  1 30 

Paton,  Noel,  147 

Pear,  the,  10,  36 

Peel  of  fruits,  6 

Pender,  xxvi 

Perilymph,  229 

Perineurium,  75,  162 

Peripheric  nerves,  75,  76 

Persistence  of  vision,  221 

Personal  capacity,  57 

Peters,  132 

Phalaris,  sense  of  light  of,  130 

Phaseolus  muUiflorus,  120,  122 

Phillips,  226 

Pigment  cells,  221,  227,  228 

Piper,  experiments  of,  98 

Plain  muscle,  99,  101,  144,  178,  184, 

et  seq.,  203 
Plane  of  Hensen,  151 
Plants  grovv-n  in  pots,  7,  9,  40 

„        in  dry  climates,  133 

,,      ,  how  electrified,  8 

,,        resting,  37 
Platinum,  secondary  action  of,  7 
Plexus  of  Auerbach,  167 
Plexuses  of  involuntary  muscle,  167 
Pneumonia,  254 
Poisoning,  vegetable,  277 
Polar  bodies,  110 

„       regions,  276 
Polarisation,  35,  36,  67,  68 
Polarity,  difference  of  in  hands,  61 

et  seq. 
Pons  varolii,  171,  215 
Positive  and  negative,  82 
Potato,  the,  15 

Potatoes,  experiments  with,  40 
Power  of  taste  and  smell  in  plants, 

128 
Preece,  xxv,  91 

Primary  or  secondary  cells  ?  36 
Pronuclei,  male  and  female,  110 


INDEX 


289 


Propagation  of  impulse,  76,  89 

„  of  stimulus  in  plants, 

136 
Protoplasm,  interstitial,  213 
„         ,  death  of,  139 
,,         ,  movement  of  in  plants, 
135,  138,  158 
Protoplasm,  network  in,  113,  114 
Protozoa,  112 
Purkinje's  cells,  168 
„  fibres,  99 

Pyorrhoea,  258 
Pyrexia,  local,  232,  244,  253  et  seq^ 

Q 

Quantity  and  tension,  198 
Quince,  the,  10,  17,  36 


R 


Radcliffe,  32 

Ranvier,   122 

,,        ,  band  of,  195 

„        ,  nodes  of,  192,  196 

Rate  of  propagation  of  nerve  im- 
pulse, 78,  89,  98,  213 

Rate  of  stimulation,  98 

Rays  of  light,  219  et  seq. 

Reduction-division,  110 

Reflex  action,  98,  212,  214 

Reissner,  membrane  of,  231 

Relative  resistance  of  gutta-percha, 
251 

Relays,  system  of  in  the  bodv,  74 

Repair  outfit,  16,  31 

Reseda  odoraia,  protoplasm  of,  124 

Resin  in  plants,  134 

Resistance  of  animal  tissues,  79 

,,  ,,  nerves  compared,  79 

„  „  skin,  69 

Response  of  muscles  and  nerves  to 
stimulation,  178  et  seq. 

Resting  nucleus,   104 

Retardation,  74,  76,  78,  91 

Retina,  221  et  seq. 

Rhubarb,  capacity  of,  19 
,,        ,  leaves  of,  277 

Rhythmic  movement  in  plants,  135 

Rice,  grain  of,  113 
,,    plant,  39 

Rigor  in  plants,  143 

Rind  of  fruits,  6 

Robertson,  M'Gregor,  55,  175 
„         ,  A.  White,  vii 

Rockwell,  49 

Rods  and  cones,  221 

Rosenthal,  75  et  seq.,  116,  166,  175 

Ross,  Earl  of,  218 


Saccule,  229 

Sachs,  4,  43, 118, 121, 126, 130, 137, 

143,  158 
Salivary  gland,  section  through,  123 
Salts  in  blood  plasma,  142 

,,       ,,   vegetables,  127 
Saprophyte,  113 
Sarcolemma,    145,    150,    153,    161, 

165,  167,  251 
Sarcomeres,  52,  97,  147  et  seq.,  155, 

161,  166,  180 
Sarcous  substance,  145,  188 
Savoy  cabbage,  43 
Scala  tympani,  229 

„      vestibule,  229 
Schafer,   103,   105,    108,    UO,   115, 

118,  120,  122,  124,  138,  153,  168, 

185,  189,  204,  214,  224 
Schenck, 5 
Schizomycetes,  112 
Schultze,  207,  210,  221,  224 
Schwann,  white  substance  of,  193 
Sciatica,  158,  258 
Sciatic  nerve,  75,  98,  122,  162 

,,        plexus,  75 
Sclerenchymatous  fibre,  123 
Scorzonera    hispanica,    laticiferous 

vessels  of,  126,  127 
Screened  cable,  163 
Sebaceous  glands,  56,  65,  255,  258 
,,         secretion,  purpose  of,  133 
Secondary  action  of  platinum,  7 
Secretion  of  nut  seeds,  26  et  seq. 
Seed  substance,  electrification  of,  24 
Seeds  in  their  electrical  aspect,  22 

et  seq. 
Segmentation  of  the  ovum,  110 
Selenium,  219,  223 
„        cell,  217 
,,         eye,  218 
Sense-organs  in  plants,  128,  130 
Sensory  nerves,  194,  200,  203,  212, 

214,  216,  231,  256 
Sensory  nerves  of  plants,  130,  157 
„      nucleus,  215 
„      nuclei,  216 
Sexual  reproduction,  112 
Sharpey,  147 
Sherrington,  85 
Siemens,  218 
Sight  in  plants,  128 
Sivewright,  91 
Skin  currents,  88 

,,     resistance,  69 
Sleeping  sickness,  275 
Smirnow,  124 
Smith,  Willoughby,  218 
Soil,  application  of  electricity  to,  3 

U 


290 


INDEX 


Somatic  cells,  118 

Some  evidences  of  the  law,  118  et 

seq. 
Source  of  energy,  85 
Specific  energy  of  tendrils,  131 

„       inductive  capacity,  81,  89, 

100 
Spermatozoids,  112,  119 
Spermatozoon,  110 
Sperm  cell,  110 

„     and  germ  nuclei,  110 
Spinal  cord,  section  of,  120 

,,     ganglion  cells,  200 
Spindle-fibres,  105,  107 
Spirem,  103 
Spirogyra,  112 
Stapes,  228 
Starch  cells,  113 
Starch-sugars  of  plants,  158 
Static  charge  in  body,  53 
Stewart,  192 
Stimuli,  various  forms  of,   139  et 

seq. 
Stimuli  and  the  amoeba,  139 

„  not    various    forms    of 

energy,  154 
Stimulation  of  plants,  39,  40,  129, 

136 
Stimulation,  rate  of,  98 
Stomata,  129 
Stone,  xxviii 
Storage  cells,  54,  200,  202 

„  of  energy,  87 
Strasburger,  118,  124 
Striated  muscular  fibre,  97,  99,  100, 

144,  147  et  seq.,  165,  166,  184 
String  galvanometer,  68 
Structmre  of  the  body  electrical,  71, 

74 
Submarine  cable,  core  of,  163 
Sugar-glycogen  of  man,  158 
Suggestion,  68 
Sulphur,  100 

Sweat-glands  and  deflections,  65 
Swede,  the,  12 
Sylvian  ossicle,  229 
Sympathetic  ganglia,  171,  204 

„  system,  87, 196  et  seq., 

204 
Synapses,  74,  76,  78 
Synapses  and  dendrons,  168  et  seq., 

212,  213 
System  of  relays  in  the  body,  74 
Szczepanik,  219,  226 
Szymonowicz,  166 

T 

Tainter,  218 

Tea  and  tobacco  plants,  278 


Telectroscope,  219 
Temperature  of  the  body,  252 
Temporal  bone,  228 
Tendrils,  specific  energy  of,  131 
Tension  and  quantity,  198 
Tensor  tympani,  229 
Termination  of  nerves  in  muscle, 

165 
Testing,  note  for  guidance  in,  44 

„         the  body,  89 
Thomson,  117 
Thornton,  202,  222,  230 
Thumb-pressure  on  electrodes,  69 
Thumbs  and  fingers,  signs  of,  63  et 

seq. 
Thunderstorms,  267  et  seq. 
Toad,  nerve  energy  of,  156 
Tobacco  and  tea,  278 
Tomato,  the,  11 

,,       plants,  experiment  with,  40 
Tortoise,  nerve  energy  of,  156 
Tradescantia,  section  of,  125 

„  ,  staminal  hairs  of,  135 

Transpiration  in  plants,  133 
Trench  foot,  63 
Trichomes,  112 
Tropics,  health  in  the,  275 
Trowbridge,  52 
Tubers,  14 

Turgidity  in  plant  organs,  135 
Turner,  203 
Turnip,  the,  12,  13,  20 
Tympanum,  228 

U 

Ultra-violet  rays  and  plants,  130 
Unipolar  cells,  121,  194,  201,  203, 

205,  210,  214,  216 
Units,  electrical,  245 
Urates  in  the  ear,  232 
JJsnea  barbata,  section  of,  121 
Utricle,  229 

V 

Vagus  nerves,  182,  259 
Van't  Hoff,  73 
Various  "  faults,"  259 

„       forms  of  stimuli,  139  et  seq. 
Vascular  connective  tissues,  87 

,,        system,  126 
Vaso-motor     and     vaso-inhibitory 

nerve-fibres,  86 
VaucheHa  Sessilis,  spore  of,  120 
Vegetable  cells,  constancy  of,  37 

„  poisoning,  277 

,,  protoplasm,  129 

Velocity  of  ions,  250 

„        „    nerve   conduction    and 
heat,  252 


INDEX 


291 


Velocity  of  nerve  impulse,  78,  89, 

98,  213 
Venation  of  leaf,  44 
Vestibule,  the,  229 
Vines,  4,  114,  132 
Viola    tricolor,    glandular    colleter 

from,  123 
Vision,  persistence  of,  221 
Visual  impulses,  222  et  seq. 

„      purple,  223,  228 
Volcanoes,  273 
Volta,  50 
Voltaic  pile,  51 
Voluntary  muscle,  97,  99,  100,  144 

147  et  seq.,  165,  166,  184,  216 
Voluntary  muscle,  nerve  fibres  of, 

150 
Voluntary  system,  86,  97,  216 


W 

VVauace,  5 

Ward,  275 

Water  in  its  relation  to  plant  life,  38 

Wax  in  plants,  133 

Wheat,  grain  of,  113 

Womb,  section  of  pregnant,  124 

Wundt,  155 


Yellow  fever,  275 

Z 

Zea  mays,  121 
Zygospore,  112 


COLUMBIA  UNIVERSITY 

This   book  is  due  on  the  date  indicated  below,  or  at  the 
expiration  of  a  definite  period  after  the  date  of  borrowing, 
as  provided  by  the  rules  of  the  Library  or  by  special  ar- 
rangement with  the  Librarian  in  charge. 

DATE  BORROWED 

DATE  DUE 

DATE  BORROWED 

DATE  DUE 

■PR 

:  (1  ]9B|g 

'^w^ 

C2ai638)MB0 

B161 


